Which of the following is true of elements? A.
They are always composed of only two types of matter.
B.
They are composed of only one type of matter.
C.
They are not composed of any type of matter.
D.
They are composed of two or more types of matter

Apebble is thrown into a calm lake, ripples are formed from the center and move outward. the water particles in the lake travel in a circular pattern that moves up and down on the surface of a lake, and the energy travels a) diagonally. b) downward. c) horizontally. d) upward.

What is the name of the perceived change in a sound wave’s frequency due to motion between the observer and the sound source?

Ne way in which elements differ from each other is the structure of the electron cloud in each element's atoms. in an electron cloud, an electron that is farther away from the nucleus has