Atomic and mass numbers

If the atomic number of Pb (Lead) is 82 and its atomic mass is 205, how many neutrons does it have?

• 123

• 82

• 205

• 287

Hydrogen has an atomic mass of 3 and atomic number of 1. How many protons and neutrons does hydrogen have?

• 3 protons and 1 neutron

• 1 proton and 2 neutrons

• 2 protons and 1 neutron

• 1 proton and 3 neutrons

Which element is the heaviest?

• Na

• Ar

Which atom has an atomic mass of 16?

• Na

• Ar

• Ca

• O

An atom has an atomic number of 11 and an atomic mass of 23. Which of the following statements is correct?

• It has 11 protons and 11 neutrons.

• It has 11 electrons and 12 protons.

• It has 11 protons and 11 electrons.

• It has 23 protons and 11 electrons.

Which pair of particles contributes the most to the overall mass of the atom?

• Electrons and protons

• Protons and neutrons

• Electrons and neutrons

The fluorine atom has an atomic number of

• 19

• 9

The fluorine atom has an atomic number of

• 19

• 9

What is the mass number and atomic number ?

• Mass number = 7, atomic number = 14

• Mass number = 14, atomic number = 7

In an element box, the number at top is the

• atomic number

• atomic name

• atomic mass

• atomic symbol