Valence Electrons, Chemical Changes and Chemical Formulas

Electrons occupying the outermost shell of an atom

• Ions

• Cation

• Valence Electrons

• Anion

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

Most atoms with more than one energy level need this many valence electrons to be stable.

• 2

• 4

• 6

• 8

Most atoms with one energy level need this many valence electrons to be stable.

• 2

• 4

• 6

• 8

Match the following

• Chemically Reactive: Lithium

• 
• Chemically Reactive: Potassium

• 
• Stable; Helium

• 
• Stable; Argon

• 

Tags

NGSS.MS-PS1-1

Match the following

• 1 valence electron with 19 total electrons

• 
• 1 valence electron with 3 total electrons

• 
• 8 valence electrons with 18 total protons

• 
• 2 valence electrons

• 

Tags

NGSS.MS-PS1-1

Evidence of a chemical reactions is anything that shows - 

• a new substance has formed
• a solid dissolved in a liquid
• interaction between 2 gases
• a change in the state of matter

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which of the following is evidence of a chemical reaction? (Choose all that apply.)

• Tearing paper.

• Unnatural change in color.

• Production of a gas.

• Change in temperature.

• Production of a precipitate. (2 liquids mix and form a solid.)

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

The group an element belongs to is

• the number at the top of a column that shows the number of valence electrons

• the number at the top of a column that shows the number of energy levels

• the number at the beginning of each row that shows the number of valence electrons.

• the number at the beginning of each row that shows the number of energy levels.

The period an element belongs to is

• the number at the top of a column that shows the number of valence electrons

• the number at the top of a column that shows the number of energy levels

• the number at the beginning of each row that shows the number of valence electrons.

• the number at the beginning of each row that shows the number of energy levels.

Which of the following is a physical property? 

• rusting 
• boiling 
• rotting 
• burning