PT #091

An atom has 10 protons, 15 neutrons and 10 electrons what is its mass number.

• 20

• 10

• 35

• 25

Potassium-39 has how many neutrons?

• 19

• 18

• 20

• 21

What is the number of protons that the element in this image contains?

• 14

• 7

• 15

• 18

Choose the correct electron configuration for Chlorine (Cl).

• 1s² 2s² 2p¹

• 1s² 2s² 2p⁶ 3s²

• 1s² 2s² 2p⁶ 3s² 3p⁵

Which element is 1s2 2s2 2p6 3s2 3p6 4s2 3d7?

• Cobalt

• Nickel

• Manganese

• Chromium

This orbital diagram represents:  

• C
• B
• N
• O