Periodic Table

The atomic number is equal to the number of __________

• Electrons

• Neutrons

• Sum of protons and neutrons

An atom has 17 protons, 17 electrons and 18 protons. Determine its mass number.

• 17

• 34

• 35

Chlorine-35 and Chlorine-37 are two atoms of the same element. What are they called?

Which element has the atomic number of 15?

Which of the following elements belong to period one of the periodic table?

• Lithium, sodium, potassium

• Beryllium, magnesium, calcium

• Hydrogen, lithium

What is the electron configuration of an element with the mass number of 52 and atomic number of 25?

• 2.8.8.5

• 2.8.8.4

• 2.8.8.6

• 2.8.8.7

What is the number of neutrons in an element with the mass number of 52 and atomic number of 25?

An element T is in period 3 and group II of the periodic table. What is its electron configuration and atomic number?

• 2.8.2; 13

• 2.3; 5

• 2.8.2; 12

• 2.8.3; 13

Naturally occuring magnesium has 3 isotopes, Mg-24, Mg-25 and Mg-26. If Mg-24 has a relative abundance of 79% and the other two isotopes occur in equal amounts, calculate the relative atomic mass of magnesium.

• 24.32

• 24.33

• 24.15

• 24.23

Which element belongs to period 2 group IV?