What is the difference between a helium atom and an alpha particle

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.

Suppose the universe were completely empty except for one object-a solid sphere moving through space of 100 km/s. what sort of path would the object be moving in? explain your answer

The atomic number, or number, is the described as the number of in the nucleus of an chemical element.