Look at the graph below. which elements together make up seven percent of the earth’s crust? calcium and iron calcium and sodium potassium and magnesium potassium and sodium

Complete the sentence to describe how light behaves as it relates to its nature (waves or particles). light travels as blank and interacts with matter as blank

Examine the nuclear reacti why is this classified as a nuclear reaction rather than a chemical reaction? it is not balanced. a new compound is formed. a change has occurred in a nucleus. a new element has been formed.

Arunner is jogging at a steady 3.6 km/hr. when the runner is 2.9 km from the finish line, a bird begins flying from the runner to the finish line at 14.4 km/hr (4 times as fast as the runner). when the bird reaches the finish line, it turns around and flies back to the runner. even though the bird is a dodo, we will assume that it occupies only one point in space, i.e., a zero-length bird. how far does the bird travel? (b) after this first encounter, the bird then turns around and flies from the runner back to the finish line, turns around again and flies back to the runner. the bird repeats the back and forth trips until the runner reaches the finish line. how far does the bird travel from the beginning? (i.e. include the distance traveled to the first encounter)