Chemistry Review

When an atom loses an electron, it becomes a

• positive ion

• negative ion

• neutral ion

• neutral atom

How does oxygen become an oxide ion?

• it loses 2 electrons

• it gains 2 electrons

• it shares electrons

• it releases energy

Valence electrons are found

• in the innermost energy level of an atom

• in the middle energy levels of an atom

• in the outermost energy levels of an atom

In a covalent bond, electrons are

• Gained

• Pulled apart

• Shared

• In the nucleus

A substance made up of atoms of two or more different elements joined by chemical bonds

• Compound

• Heterogeneous Mixture

• Homogeneous Mixture

• Solution

Pure substance that consists entirely of one type of atom.

• Solution

• Mixture

• Compound

• Element

Which of the chemical equations in the image best supports the Law of Conservation of Matter?

• A

• B

• C

• D

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Why do people use coefficients?

• to help multiply the equation

• for the equation to be unbalanced

• to subtract

• to balance equations

Tags

NGSS.MS-PS1-5

Cations

• Gain electrons, has an overall positive charge

• Lose electrons, has an overall positive charge

• Lose electrons, has an overall negative charge

• Gain electrons, has an overall negative charge

How does calcium become an calcium ion?

• it loses 2 electrons

• it gains 2 electrons