横向
1
Path of a planet around the sun
4
Smallest unit of an element
6
Gas form of a liquid
7
Second lightest element
8
Hottest planet in solar system
13
Substance with pH below 7
纵向
2
Chemical element in table salt
3
Preserved remains of ancient life
5
Disturbance that transfers energy
9
Magnetic metallic element
10
Nerve cell in the brain
11
Natural satellite of Earth
12
Ball of burning gas in space