横向
1
Mass per unit volume
5
Tectonic landmass section
6
Compound containing oxygen
7
Magnetic metallic element
9
Smallest unit of an element
11
Second lightest element
12
Molten rock beneath Earth surface
纵向
2
Naturally occurring inorganic solid
3
Unit of electric potential
4
Center of an atom or cell
8
Force that attracts objects together
10
Biological catalyst