Find the atomic number, symbol, mass number?

Question

Could someone check to see if I did this right? I was given an atomic number or symbol of these atoms and I had to find the rest. Should I round up the neutron number or one of the others?

1)Atomic number: 11 Symbol: Na Mass Number: 22.989 Proton Number:11 Neutron Number:11 Electron Number:11

2)Atomic number: 13 Symbol: Al Mass Number: 26.981 Proton Number:13 Neutron Number:13 Electron Number:13

3)Atomic number: 26 Symbol: Fe Mass Number: 55.847 Proton Number:26 Neutron Number:29 Electron Number:26

Answer 1

All of this information is available on a decent Periodic Table.

Answer 2

No, you have a couple of errors,

1 - Na has 11 electrons and protons, but 12 neutrons (23-11)
2 - Al has 13 electrons and protons, but 14 neutrons (27-13)
3 - Fe has 26 electrons and protons, but 30 neutrons (56-26)

The isotopes of these elements account for the varying numbers which are not whole numbers in the periodice table. I usually just round up if it .8 or.9 or round down if it is .1

Answer 3

The atomic mass, the sum of the mass of protons and neutrons, is typically the number beneath the symbol.

Answer 4

In all cases, increase the neutron number.

Answer 5

All you need to do is look at the Periodic Table of Elements. It has all that information on it providing you understand how to read the Table.