NBC 8 UNIT 2 Review

Which electron configuration belongs to Chlorine (Cl)?

• 1s² 2s² 2p⁶ 3s² 3p⁵
• 1s² 2s² 2p⁶ 3s² 3p⁶
• 1s² 2s² 2p⁶ 3s² 3p⁷

What atom matches this electron configuration?
1s²2s²2p⁶3s²

• Neon
• Magnesium
• Aluminum
• Potassium

Choose the correct electron configuration for Beryllium (Be).

• 1s¹

• 1s² 2s²

• 1s² 2s² 2p¹

24.1% of all the isotopes of a an element have a mass of 75.23 amu, 48.7% have a mass of 74.61 amu, and 27.2% have a mass of 75.20 amu.
What is the average mass of this element?

• 74.92 amu
• 24.97 amu
• 75.01 amu
• 74.51 amu

Positive ions form when atoms _________ valence electrons.

• lose
• gain
• share
• gain or share

When two atoms of the same element have different masses, they are called ______, and have a different number of ______.

• Neutrons; Isotopes

• Atoms; Isotopes

• Isotopes; Protons

• Isotopes; Neutrons

Would you rather be forced to sing along or dance to every single song you hear?