Answer:






Explanation:
In the first nucleus we are told that there are two protons and one neutron. Let us remember that the mass number = number of protons + number of neutrons.
This implies that, for the first specie the mass number is 3, for the second specie the mass number is 6 and the third specie has a mass number of 7 and so on. The mass number is indicated as a superscript.
The atomic number is the number of protons in the nucleus of the atom and helps us to identify the atom. It is always written as a subscript as shown.
15c - 1.2m
1c - 1.2/15 = 0.08m
65c - 5.2m
Answer:
14 g of N2
Explanation:
If we look at the options, we will notice that the correct answer needs to be a gas that has about half of the molecular mass of the gas.
If we consider nitrogen gas whose molecular mass is 28g/mol, half of the molecular mass is 14 g.
So;
28g of N2 contains 6.02 × 10^23 molecules of N2
14g of N2 contains 14 × 6.02 × 10^23 /28
= 3.0 x 10^23