ATOMIC NUMBER & MASS NUMBER

What is the atomic number of an element that has 8 protons?

• 8

• 11

• 9

• 10

The atomic number of an element is 6. What is the name of this element?

• Hydrogen

• Helium

• Carbon

• Nitrogen

An atom of aluminum (Al) has 13 protons and 14 neutrons. Calculate its mass number.

• 1

• 13

• 24

• 27

The periodic table shows that chlorine (Cl) has an atomic number of 17.

• a. How many protons does a chlorine atom have?

• 15

• 17

• 27

• 35

An atom of magnesium (Mg) has an atomic number of 12 and a mass number of 24.

• a. How many neutrons does this atom have?

• 12

• 24

• 36

• 42

The element sulfur (S) has an atomic number of 16. One of its isotopes has a mass number of 34.

• a. Calculate the number of neutrons in this isotope.

An isotope of oxygen has a mass number of 18. The atomic number of oxygen is 8.

• a. How many neutrons does this isotope contain?

The element boron (B) has an atomic number of 5. Its most common isotope has a mass number of 11.

• a. How many neutrons are in this isotope of boron?

The atomic number determines the identity of an element and its position in the periodic table.

• TRUE

• FALSE

The mass number represents the total number of protons and neutrons in an atom.

• TRUE

• FALSE