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# Carbon number of protons, neutrons and electrons

### How to find the Number of Protons, Electrons, Neutrons for

In this video we'll use the Periodic table and a few simple rules to find the protons, electrons, and neutrons for the element Carbon (C). From the Periodic. Carbon: Symbol: C: Atomic Number: 6: Number of Protons: 6: Number of Neutrons: 6: Number of Electrons: 6: Melting Point: 3500.0° C: Boiling Point: 4827.0° C: Density: 2.62 grams per cubic centimeter: Normal Phase: Solid: There are almost 10 million carbon compounds and they are studied in organic chemistry classes. Some of the most. Atomic Number - Protons, Electrons and Neutrons in Carbon Carbon is a chemical element with atomic number 6 which means there are 6 protons in its nucleus. Total number of protons in the nucleus is called the atomic number of the atom and is given the symbol Z Carbon is a chemical element with atomic number 6 which means there are 6 protons and 6 electrons in the atomic structure. The chemical symbol for Carbon is C. The atom consist of a small but massive nucleus surrounded by a cloud of rapidly moving electrons. The nucleus is composed of protons and neutrons 12 C, 13 C, and 14 C are isotopes of carbon (Z = 6) and therefore contain six protons. If the atoms are neutral, they also must contain six electrons. The only difference between these isotopes is the number of neutrons in the nucleus. 12 C: 6 electrons, 6 protons, and 6 neutrons. 13 C: 6 electrons, 6 protons, and 7 neutrons

In an atom of carbon-11, the number of protons is 6. The number of electrons is 6. The number of neutrons is 5 which is calculated by subtracting the proton count from the atomic mass value Before you start, take a look at carbon on the periodic table. It has an atomic number of 6. That means a carbon atom has 6 protons, 6 neutrons, and 6 electrons. Since carbon is in the second row (or second period), it has 2 electron orbits

### #6 - Carbon -

1. So, carbon-13 has 7 neutrons, because carbon has atomic number 6. Carbon-12 is composed of 6 protons, 6 neutrons, and 6 electrons. Carbon-14 can also be produced in the atmosphere by other neutron reactions, including in particular 13C (n,γ)14C and 17O (n,α)14C
2. carbon number of protons, neutrons, and electrons. January 12th, 2021. Atomic Number Doing a quick calculation, we know that carbon-12, or 12 C, has six protons; therefore, 12 - 6 = 6 neutrons. The difference between the neutron number and the atomic number is known as the neutron excess: D = N - Z = A - 2Z
3. For hydrogen, 1.008 is closer to 1 than 2, so let's call it 1. Number of Neutrons = Mass Number - Number of Protons = 1 - 1 = 0. For zinc, the atomic weight is 65.39, so the mass number is closest to 65. Number of Neutrons = 65 - 30 = 35. Cite this Article
4. What is the number of protons, neutrons, and electrons in 1 gram of carbon-14 atoms? The molar mass of C-14 is 14.003 g/mol, so 1 g = 1/14.003 mol ≈ 0.071 mol. Avogadro's number is 6.022 × 10²³ atoms/mol, so 1 g contains (6.022 × 10²³ atoms/mol) (0.071 mol) = 4.28 × 10²² atoms
5. Carbon-14 has 6 protons and 8 neutrons. 6 + 8 = 14. The isotope you described exists. According to the Wikipedia page of Carbon-14 it decays via beta decay. After beta decay we have one neutron less abd a proton and an electron more. 8 - 1 = 7 and 6 + 1 = 7
6. The atomic number (number at the top) is the amount of protons and the amount of electrons. So if an element has an atomic number of 5, you know that it has 5 protons and 5 electrons. The atomic mass (number at the bottom) is the amount of protons and neutrons added together. Whichever you know, you subtract from the atomic mass

In carbon's case, a neutral carbon atom has 6 protons inside the nucleus and 6 electrons outside the nucleus. So, to figure out the number of protons and electrons present in a neutral atom, find the element in the Periodic Table and look for its atomic number Isotopes of Carbon. Carbon isotopes come in three forms. By far the most common isotope of carbon is carbon-12 (12 C), which contains six neutrons in addition to its six protons.The next heaviest carbon isotope, carbon-13 (13 C), has seven neutrons.Both 12 C and 13 C are called stable isotopes since they do not decay into other forms or elements over time For example, a typical carbon atom has six protons and six neutrons, and it has an atomic weight of 12 amu. A carbon also has six electrons, but they are so small that they don't contribute to carbon's weight. An element is defined by the number of protons in its nucleus No. of atoms present in 1 mole of Carbon = N A = 6.023×1023 As 1 mole of carbon contains 6 electrons, 6 protons and 6 neutrons. ∴ No. of electrons in 6.023×1023 atoms of carbon= 6×6.023×102 If a neutral atom has 1 proton, it must have 1 electron. If a neutral atom has 2 protons, it must have 2 electrons. If a neutral atom has 10 protons, it must have 10 electrons. You get the idea. In order to be neutral, an atom must have the same number of electrons and protons

### Carbon - Periodic Table and Atomic Propertie

• Carbon having 6 protons, 6 neutrons and 6 electrons has no more to do with melanin than it does to do with tomato sauce or bananas. Carbon may be the mark of the beast, but melanin is not carbon. Melanin is a chemical. Carbon is an element. Melanin is not carbon because melanin has a chemical formula
• Carbon has 3 isotopes. Carbon-12, Carbon-13, and Carbon-14. All of them have an atomic number of 6, which means all of them have 6 protons (if they had different numbers of protons, they'd be different elements). Since they all have 6 protons, in their elemental forms, they all have 6 electrons, too. Carbon-12: Atomic number: 6. Mass number: 12
• e the number of protons, electrons, and neutrons of an element with a given mass number. All atoms of the same element have the same number of protons, but some may have different numbers of neutrons. For example, all carbon atoms have six protons, and most have six neutrons as well
• If the element is carbon then it always has 6 protons and 6 electrons in an atom but the number of neutrons can be different. These are simply called carbon 12, carbon 13 and carbon 14. Isotopes of carbon

### Carbon - Atomic Number - C - Periodic Tabl

Number of Neutrons = Mass Number - Atomic Number; Mass Number = Sum of Protons and Neutrons; Finding Protons, Neutrons, and Electrons of Isotopes. Isotopes are atoms of the same element with the same proton number, but different number of neutrons. For example, carbon - 12, carbon - 13 and carbon - 14 are three isotopes of Carbon, each. Question. The atomic number of a sodium atom is 11 and its mass number is 23. Calculate the number of protons, neutrons and electrons it contains

### Video: Structure of the Atom - Purdue Universit

Calculate the number of protons, neutrons and electrons for the following elelments. You will need your periodic table of elelents. Carbon (c) Proton - 6 Neutron - 6 Electron - 6. Nitrogen (N) Proton - 7 Neutron - 7 protons, electrons and neutrons 20 Terms. Josh38248. First 26 elements on periodic table 26 Terms The atomic number of a sodium atom is 11 and its mass number is 23. Because there are 6 protons in the atom, there must be 6ELECTRONS in the atom. 12 C, 13 C, and 14 C are isotopes of carbon (Z = 6) and therefore contain six protons. The mass number is a count of the number of particles in an atom's nucleus. Calculate the number of protons, neutrons and electrons it contains. One fairly common. The number of protons is equal to the number of electrons in neutral atoms. This is the atomic number. Proton is positively charged (+1), a neutron is neutral in charge, and the electron is negatively charged (-1) The number of neutrons can vary in the nucleus to produce isotopes, which are atoms of the same element that have different numbers. The total numbers of neutrons, protons, and electrons in {eq}^{35}Cl^- {/eq} are (D). 18 neutrons, 17 protons, 18 electrons. Become a member and unlock all Study Answers Try it risk-free for 30 day

Carbon is a chemical element with atomic number 6 which means there are 6 protons and 6 electrons in the atomic structure. The chemical symbol for Carbon is C. The atom consist of a small but massive nucleus surrounded by a cloud of rapidly moving electrons. The nucleus is composed of protons and neutrons carbon number of protons, neutrons, and electrons Jan 12 2021 4:42 AM. Embe Name: Carbon Symbol: C Atomic Number: 6 Atomic Mass: 12.0107 amu Melting Point: 3500.0 °C (3773.15 K, 6332.0 °F) Boiling Point: 4827.0 °C (5100.15 K, 8720.6 °F) Number of Protons/Electrons: 6 Number of Neutrons: 6 Classification: Non-metal Crystal Structure: Hexagonal Density @ 293 K: 2.62 g/cm 3 Color: May be black Atomic Structur

The element carbon (\(C\)) has an atomic number of 6, which means that all neutral carbon atoms contain 6 protons and 6 electrons. In a typical sample of carbon-containing material, 98.89% of the carbon atoms also contain 6 neutrons, so each has a mass number of 12 The number of neutrons in an atom of carbon that has a mass number of 12 is six. How many electrons are there in an atom of carbon? Atoms consist of positively charged protons, neutral neutrons, and negatively charged electrons The neutron number however are, 6, 7, and 8, respectively, in each of these Carbon isotopes. The plus sign means that this is a positively charged ion. Calculate the number of protons, neutrons and electrons it contains. It is simple to know the number of protons, electrons, and neutrons by using the periodic table Atomic no. Protons, Neutrons and Electrons of all the Elements: Shell Diagram: 1: Hydrogen has 1 proton, 0 neutron and 1 electron: 2: Helium has 2 protons, 2 neutrons and 2 electrons: 3: Lithium has 3 protons, 4 neutrons and 3 electrons: 4: Beryllium has 4 protons, 5 neutrons and 4 electrons: 5: Boron has 5 protons, 6 neutrons and 5 electrons: 6: Carbon has 6 protons, 6 neutrons and 6 electrons

2. How many protons, neutrons, and electrons are there in a) a carbon atom of mass number 13? protons neutrons electrons b) a germanium atom of mass number 78 protons neutrons electrons- Write the element corresponding to the following Atoms—and the protons, neutrons, and electrons that compose them—are extremely small. For example, a carbon atom weighs less than 2 10 −23 g, and an electron has a charge of less than 2 10 −19 C (coulomb). When describing the properties of tiny objects such as atoms, we use appropriately small units of measure, such as the atomic mass unit (amu) and the fundamental unit of charge (e) proton and electron are exactly the same size but opposite. ˚e same number of protons and electrons exactly cancel one another in a neutral atom. Note: ˝e picture shows a simple model of the carbon atom. It illustrates some basic informa-tion like the number of protons and neutrons in the nucleus. It also shows that the number of Here are three isotopes of carbon (C). The atomic number for C is 6, so that all carbon atoms have 6 protons. C 12: 6 protons plus 6 neutrons. C 13: 6 protons plus 7 neutrons. C 14: 6 protons plus 8 neutrons. The C 14 ISOTOPE IS UNSTABLE and thus, undergoes radioactive decay! The result of radioactive decay is that C 14 -> N 14, an isotope of.

Build an atom out of protons, neutrons, and electrons, and see how the element, charge, and mass change. Then play a game to test your ideas! Sample Learning Goals Use the number of protons, neutrons, and electrons to draw a model of the atom, identify the element, and determine the mass and charge The atomic number for any element can be found by looking at a periodic table, indicated by the whole number beside the symbol for that element. For example, being made up of carbon, the lead has six protons, just like every other carbon atom. All protons have a positive +1 charge of graphite. Going deeper, graphite is made of carbon atoms. Deeper still, each carbon atom is made of protons, neutrons, and electrons. In this lesson, you will explore these subatomic particles and their charges.!!!!! 1.!Label the nucleus (protons, neutrons) and electrons in the drawing of a carbon atom above.

The number of protons is the atomic number, and the number of protons plus neutrons is the atomic mass. For hydrogen, the atomic mass is 1 because there is one proton and no neutrons. For helium, it is 4: two protons and two neutrons. For most of the 16 lightest elements (up to oxygen) the number of neutrons is equal to the number of protons Protons, Neutrons, and Electrons Practice Worksheet. Calculating the number of each particle in an atom: # Protons = Atomic Number # Electrons = Protons # Neutrons = Atomic Mass - Atomic Number OR Big # - Small # Use the periodic table to find the numbers of protons, neutrons, and electrons for atoms of the following elements B. Mass Number Equals Protons plus Neutrons Each atom also has a mass number, denoted by the symbol A. The mass number of an atom is equal to the number of protons plus the number of neutrons that it contains. In other words, the number of neutrons in any atom is its mass number minus its atomic number ### How many protons, neutrons, and electrons are there in an

1. 2.1.4 State the relative masses and relative charges of protons, neutrons and electrons. Calculate the number of protons, neutrons and electrons in atoms from the identity, mass number, atomic number and/or charge. 2.1.5 State the position of protons, neutrons and electrons. Draw and interpret planetary models for elements up to Z=18
2. Neutrons are relatively heavy particles with no charge and a mass of 1.0087 amu. Electrons are light particles with a charge of 1− and a mass of 0.00055 amu. The number of protons in the nucleus is called the atomic number (Z) and is the property that defines an atom's elemental identity
3. The total number of protons, electrons and neutrons in 12 g of carbon is 6×6.023×1023 i.e 36.13×1023. There are3 same no of protons, neutrons, and electrons. Thus, the total no of protons, neutrons and electrons is 12 g of 612. . C = 3×36.13×1023 = 1.084×1025. Hence, the correct option is A
4. The overall charge on an atom is 0, therefore there must be an equal number of protons and electrons in an atom so that the charges cancel out. So in chlorine, we can see that the atomic number is 17. This means that each chlorine atom has 17 protons and therefore must also have 17 electrons. The nucleus of an atom contains protons and neutrons
5. So number of electrons in is also 6.The number of neutrons present in the carbon atom can be calculated as follows:Number of neutrons = Mass number (A) -Atomic number (Z)Substitute 13 for mass number and 6 for the atomic number in the above equation, we get: So the number of protons, electrons, and neutrons in are 6, 6, and 7 respectively
6. of protons electrons neutrons present in one carbon atom = 6. No of protons electrons neutrons present in 12 gram of carbon atom is 6*6.023*10^23 = 36.138*10^23. The question says no of protons,electrons and neutrons present in it. Therefore the answer is 3*36.138*10^23 = 1.08*10^2
7. An atom of Cu-63 has 34 neutrons and an atom of Cu-65 has 36 neutrons. 27- The total number of electrons in an atom of Cu-65 is 29 because copper has atomic number of 29, which simply means that an atom of copper has 29 protons and 29 electrons

### Ology - Amn

: protons, neutrons, and electrons. Protons. Exhibit a positive charge. Found in the nucleus. Abbreviated p+ . Mass of 1.67 x 10-24g . The number of protons is equivalent to the element's atomic number. Atomic # = # of p+. Electrons. Exhibit a negative charge. Found outside of the nucleus. Abbreviated e- Mass of 9.11 x 10-28g. The number of. Example: Let's decide the number of protons, neutrons, and electrons in the accompanying isotopes. 12C 13C 14C 14N The various isotopes of a component are distinguished by composing the mass number of the molecule in the upper left corner of the image for the component. 12C, 13C, and 14C are isotopes of carbon (Z = 6) and along these lines. So total electrons present are 16+6=22 electrons Just the facts Atomic Number (6 protons, 6 neutrons and 6 electrons) and carbon-13 (6 protons, 7 neutrons and 6 electrons) Carbon: From stars to life As the sixth-most abundant element in the universe, carbon forms in the belly of stars in a reaction called the triple-alpha process,

### how many protons, neutrons, and electrons does carbon hav

• This is how this works. The number given after the atom name indicates the number of protons plus neutrons in an atom or ion. Atoms of both isotopes of carbon contain 6 protons. Atoms of carbon-12 have 6 neutrons, while atoms of carbon-14 contain 8 neutrons.A neutral atom would have the same number of protons and electrons, so a neutral atom of carbon-12 or carbon-14 would have 6 electrons
• Sample Learning Goals. Define isotope using mass number, atomic number, number of protons, neutrons and electrons. Given information about an element, find the mass and name of an isotope. Give evidence to support or dispute: In nature, the chance of finding one isotope of an element is the same for all isotopes.
• For protons, the number always equals the atomic number of the element. Isotopes are simply specifying the number of neutrons and protons (together called nucleons) in the atom. So, Carbon-12, which has an atomic mass number of 12, has 6 neutrons (12 nucleons - 6 protons = 6 neutrons). Click to see full answer
• Answers ( 2) A. Alison Lindsey 9 December, 14:52. 0. Carbon. Explanation: The number of protons is equal to the atomic number of the element. For this element having 6 protons makes the atomic number 6 and makes the element Carbon. For this element 6 protons and 6 neutrons combine to make an atomic mass of 12 amus

### carbon number of protons, neutrons, and electron

• Carbon-14 (14C), or radiocarbon, is a radioactive isotope of carbon with an atomic nucleus containing 6 protons and 8 neutrons. Its presence in organic materials is the basis of the radiocarbon dating method pioneered by Willard Libby and colleagues (1949) to date archaeological, geological and hydrogeological samples
• The number of protons and neutrons combined to give us the mass number of an atom. It is represented using the letter 'A.'. As both protons and neutrons are present in the nucleus of an atom, they are together called nucleons. For example, an atom of carbon has 6 protons and 6 neutrons. Thus, its mass number is 12
• A carbon atom contains six protons and six neutrons.A. What are its atomic number and atomic weight?B. How many electrons does it have?C. How many additional electrons must it add to fill its outermost shell? How does this affect carbon's chemical behavior?D. Carbon with an atomic weight of 14 is radioactive
• Carbon-12 is the most common isotope of carbon. It has 6 protons, 6 neutrons, and 6 electrons. Of its 6 electrons, 4 are valence electrons. How many covalent bonds can a carbon atom form

### Number of Protons, Neutrons, and Electrons in an Ato

Protons electrons and neutrons quiz questions | Footprints-Science - GCSE science animations and quizzes - Deducing the number of protons, electrons and neutrons in an atom using atomic number and mass number Neon atoms have 10 protons, and a neutral atom has 10 electrons. The number of neutrons can vary, but the most common natural Every element has a nitrogen has the atomic number 7 which means it has 7 protons. Neon has different numbers of neutrons in its nucleus ### What is the number of protons, neutrons, and electrons in

To find the number of neutrons, subtract the atomic number from the mass number. Give the number of protons, neutrons, and electrons in an atom of carbon-11. 10. For example, 12 C, 13 C and 14 C are all isotopes of carbon. This chemistry video tutorial explains how to calculate the number of protons, neutrons, and electrons in an atom or in an ion The number of protons is equal to the number of electrons. What is the total number of protons and neutrons in Fluorine, F, has an atomic number of 9 and an Silver has an atomic number of 47 and atomic mass of Beryllium, Be, has an atomic number of 4 and an lithium has a atomic number of 3 and atomic mass of

### How many protons, neutrons, and electrons are in an

• Melting Point: The melting point of Carbon is -3550 º C. Molar Mass: The molar mass of Carbon is 12.01 g/mol. Number of Electrons: Carbon has 6 electrons. Number of Isotopes: Carbon has 7 isotopes. Number of Protons: Carbon has 6 protons. Specific Gravity: The specific gravity of Carbon is 1.8-3.59. Symbol: The symbol of Carbon is C
• The same number of protons and electrons exactly cancel one another in a neutral atom. Note: The picture shows a simple model of the carbon atom. It illustrates some basic informa-tion like the number of protons and neutrons in the nucleus. It also shows that the number of electrons is the same as the number of protons
• The number of electrons in an atom can also vary, but if you take a pure sample of the element under normal conditions the number of electrons is equal to the number of protons. When an atom has an equal number of protons and electrons it is called neutral, an ion is formed when electrons are either removed or added
• Iupac periodic table nuclide notation how many protons neutrons and electrons in atoms atoms and the periodic table. This isotope of carbon has 6 protons and 6 neutrons. For hydrogen the atomic number is 1 because there is one proton and no neutrons. 5 protons electrons 6 neutrons 108 rounds up to 11 is the atomic mass

### How to Find the Number of Protons, Neutrons, and Electron

• For instance, it is now known that in each atom of carbon 12, there are a set number of subatomic particles: six electrons, six protons, and six neutrons. The atom's nucleus and electrons are held.
• In the carbon-14 isotope, there are 6 protons, 8 neutrons, and 6 electrons. These are two examples of isotopes of carbon. The number of neutrons varies with the isotope
• For each of the following isotopes, write the number of protons, neutrons, and electrons. Assume all atoms are neutral. Carbon-12 Carbon-13. Carbon-14 # of protons 6 6 6 # of neutrons 6 7 8 # of electrons 6 6 6 Chromium-58 Chromium-63 # of protons 24 24 # of neutrons 34 39 # of electrons 24 24 Nitrogen-15 Nitrogen-20 # of protons 7 7 # of.

### How can we find the number of protons and electrons

STEP 3 -The number of Electrons (-) - Atoms have an overall charge of (0) neutral -Number of Protons = Number of Electrons -Xenon has an atomic number of 54, which means it has 54 protons - Number of protons = 54 - Number of Protons = Number of # of protons = atomic number # of neutrons = mass number - atomic number # of electrons = atomic number - charge. That's it! Examples. Great, lets apply the rules to some examples. # of protons = 17 # of neutrons = 37 - 17 = 20 # of electrons = 17 - 0 = 17 # of protons = 16 (the atomic number is not given, but can be found on the.

### Global Monitoring Laboratory - Carbon Cycle Greenhouse Gase

# protons # neutrons # electrons Carbon -14 Hydrogen -3 Assuming only pure elements (neutral atoms), complete the following table. Atomic Symbol Name-# Atomic Number Atomic Mass # protons # neutrons # electrons Cobalt - 60 80 117 90 38 21 19 34 7 Structure of Hydrogen atom: This implies that it contains one proton, one electron, and no neutrons ( total number of neutrons = mass number - atomic number) Carbon. Carbon has two stable isotopes - 12C and 13C. Of these isotopes, 12C has an abundance of 98.9%. It contains 6 protons, 6 electrons, and 6 neutrons Carbon isotope. Adding the two neutrons changes our atom. However, because the number of protons are the same, it is still carbon but now it is an isotope of carbon. We represent isotopes by using the chemical symbol (C for carbon) and a number. The first carbon atom with only 6 neutrons would be called 12 C or Carbon-12 A) the number of electrons. B) the number of protons plus neutrons. C) the number of protons. D) the number of electrons plus protons. E) the number of neutrons. 23) What is the mass number of an atom of potassium that has 20 neutrons? B) 19 C) 35 D) 39 E) 59 24) Consider a neutral atom with 30 protons and 34 neutrons. The atomic number of th The basics of how protons, electrons, and neutrons make up an atom. How elements relate to atoms. two three four five six nor carbon-12 which is a version of carbon will also have six neutrons you can have versions of carbon that have a different number of neutrons so the neutrons can change the electrons can change you can still have the.

### Structure & Reactivity: Atoms: Protons, Neutrons, Electron

Given an atomic number (Z) and mass number (A), you can find the number of protons, neutrons, and electrons in a neutral atom. For example, a lithium atom (Z=3, A=7 amu) contains three protons (found from Z), three electrons (as the number of protons is equal to the number of electrons in an atom), and four neutrons (7 - 3 = 4) In case of carbon-14,mass no.=14;atomic no.=06. NO. OF ELECTRONS=06=NO OF PROTONS=ATOMIC NO. NO. OF NEUTRONS=MASS NO. - ATOMIC NO. =14-06 =08. THANK YOU!! Protons, together with neutrons, are called the 'nucleons.' There are one or more protons present in every atom. The number of protons differs in each atom and forms the identity of an atom. When elements are grouped together in the periodic table, the number of protons is used as the atomic number of that element atomic number: number of protons, in a neutral atom, the number of protons=the number of electrons, The overall charge of an atom is 0. Example: Carbon (C)atomic number: 6. +6 protons -6 electrons=0 charge, the +'s cancel out the -'s! Number of protons never changes, no two different elements will ever have the same number of protons The element carbon (\ (C\)) has an atomic number of 6, which means that all neutral carbon atoms contain 6 protons and 6 electrons. The same number of protons and electrons exactly cancel one another in a neutral atom. One fairly common isotope is carbon-12, which has 6 neutrons. The mass number is a count of the number of particles in an atom. And since the atom is neutral, the number of electrons and protons are equal. For Kr, you have to look for its atomic number from the Periodic Table. From the periodic table, the atomic number of Kr is 36. Therefore to get the number of neutrons, you must subtract the atomic number (36) from the mass number ( 84) A neutral atom will have the same number of electrons is does protons. Since it has 4 protons, it must have an atomic number of 4. (That makes itberyllium.) Since it has a 4 protons and 5 neutrons, it has a mass number of 9 Atoms consist of protons, neutrons, and electrons. The isotope, carbon-12 (6 12C), contains 6 protons and 6 neutrons. Carbon-13 (13C) contains 6 protons and 7 neutrons. Carbon-14 (14C) contains 6 protons and 8 neutrons. Recall to add the number of protons (Z) and the number of neutrons to get the mass number (A) Mass Number. An atom consists of protons, neutrons, and electrons. Since the mass of electrons is negligible as compared to protons and neutrons, the mass of an atom is determined by protons and neutrons only. The total number of protons and neutrons present in one atom of an element is known as its mass number