To help predict eruptions, scientists often rely on
rock samples.

If we compare and contrast electromagnetic waves with sound waves, all but one statement is true. that is a) sound waves require a medium to travel while electromagnetic waves do not. b) electromagnetic waves can travel through the vacuum of space while sound waves cannot. c) electromagnetic waves must have a medium in which to travel, but sound waves can travel anywhere. eliminate d) sound waves must bounce off of matter in order to travel while electromagnetic waves do not require matter to be present.

Na chemical reaction, activation energy increases the of the reactants. this outcome causes the particles to collide, which results in the of new products.

In general metals get as you move from left to right across the periodic table.