(D)an atom can join with other kinds of atoms.
Basically he explained what a molecule is.
One useful point about the moment magnitude scale is that it is logarithmic, where each whole number represents a factor of 32. Therefore, the difference in two whole numbers of the magnitude means that an earthquake is 1,000 times stronger. For example, a 7.0 magnitude earthquake releases 1,000 times more energy than a 5.0 one.
The sun is a source of energy
Here are some of the animals that have names that start with S: seal, sheep, skunk, sloth, sparrow, squirrel, swan, salamander, scorpion, serval, snake, spider, stork, etc.
Hope this helps :)