Unit 3 8th Grade Changes in Matter

Where is the most energy located?

• Inner most shell

• Nucleus

• Outer most shell

Atoms are most stable with:

• 8 valence e-

• 6 valence e-

• 0 valence e-

• 4 valence e-

Unlikely to lose or share e-

• Transitional Metals

• Halogens

• Alkali Earth Metals

• Noble Gases

If something has a full shell it is :

• somewhat reactive

• non reactive

• very reactive

Reactivity ________ as you move right on the periodic table

• Stays the same

• Increases

• Decreases

Groups 1 and 2 like to _____ electrons

• gain

• share unpolar

• share polar

• lose

Hydrogen only needs ____ valence electrons to remain stable

• 8

• 6

• 4

• 2

How many atoms are in NaOH?

• 3

• 2

• 4

• 5

How many atoms are in Hg

• 2

• 1

• 3

• 4

small numbers found to the right of each element which tells how many of each element is in a compound

• subscripts

• coefficients

• variables

• elements