Question

find the number of electrons protons and neutrons in the following atoms:-
1. Carbon (Z=6) (A=12)
2. Sodium (Z=11) (A=23)
3. Calcium (Z=20) (A=40)
4. Chloride (Z=17) (A=35)
5. Oxygen (Z=8) (A=16)​

Answer 1

Answer:

1.A = 12, Z = 6 (from the periodic table), N = ? An atom of the carbon-12 isotope has a mass number of 12, an atomic number of 6, and 6 neutrons.

2.The atomic number and mass number of sodium are 11 and 23 respectively.

This suggests that number of proton in sodium =11 and number of nucleons i.e. proton and neutrons in sodium =23. Thus, number of neutrons =12 and also Since no. of protons = no. of electrons =11

So, they are similar.

3.The number of nucleons which is referred to as the mass number of an atom is 40 in case of calcium atom which is double the number of neutrons .

4.A chlorine nucleus will contain: Number of protons Z = 17. Number of protons + neutrons A = 35. Number of neutrons N = 35 - 17 = 18.

5.Oxygen has an atomic number of 8 , and the mass number of an atom is the sum of its atomic number plus its neutron number. We got the mass as 16 units, and so it'll have 16−8=8 neutrons.