Across
1
Unit of heredity
2
Molten rock beneath Earth surface
4
Center of an atom or cell
5
Icy body with a tail near the sun
7
Our home planet
9
Second lightest element
Down
1
Force that attracts objects together
3
Element found in all living things
5
Reddish electrical conductor
6
Smallest unit of an element
8
Substance with pH above 7
10
Positive particle in nucleus
11
Tissue that contracts for movement