Chemistry Final Exam #2

What is the electron configuration of the gallium ion?

• 1s² 2s² 2p⁶ 3s² 3p⁶

• 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 4p⁶

• 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰

• 1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹

Tags

NGSS.HS-PS1-1

The octet rule states that, in chemical compounds, atoms tend to have ____.

• the electron configuration of a noble gas

• more protons than electrons

• eight electrons in their principal energy level

• more electrons than protons

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

A compound held together by ionic bonds is called a ____.

• diatomic molecule

• polar compound

• covalent molecule

• salt

What is the formula unit of aluminum oxide?

• AlO

• Al₂O₃

• AlO₃

• Al₃O₂

Which of the following is true about the melting temperature of potassium chloride?

• The melting temperature is relatively high.

• The melting temperature is variable and unpredictable.

• The melting temperature is relatively low.

• Potassium chloride does not melt.

Tags

NGSS.MS-PS1-4

Which of the following is NOT a characteristic of most ionic compounds?

• They are solids.

• They have low melting points.

• When melted, they conduct an electric current.

• They are composed of metallic and nonmetallic elements.

Tags

NGSS.HS-PS1-3

Which of these elements does not exist as a diatomic molecule?

• Ne

• F

• H

• I

Why do atoms share electrons in covalent bonds?

• to become ions and attract each other

• to attain a noble-gas electron configuration

• to become more polar

• to increase their atomic numbers

Which of the following is the name given to the pairs of valence electrons that do not participate in bonding in diatomic oxygen molecules?

• unvalenced pair

• outer pair

• inner pair

• unshared pair

Tags

NGSS.HS-PS1-1

Which of the following diatomic molecules is joined by a double covalent bond?

• O₂

• Cl₂

• N₂

• He₂