What are the ratio of the compounds how would u make one like this: 1 calcium, 1 oxygen

What is the study of how matter and energy interact? a. biology b. physics c. planetary science d. chemistry

Which statement describes how phase changes can be diagrammed as a substance is heated? the phase is on the y-axis and the temperature is on the x-axis. the temperature is on the y-axis and the phase is on the x-axis. the time is on the y-axis and the temperature is on the x-axis. the temperature is on the y-axis and the time is on the x-axis.

Achange in the number of neutrons in an atom will change an blank . when the number of protons changes in an atom, a new element will form.