When does the composition of a substance does not change?

How many electrons should be shown in the lewis symbol for hydrogen?

Convert 4.57X-3m to the equivalent length in nanometers

What's the electron configuration of an N-3 ion

The molar mass of calcium chloride (cacl2) is 110.98 g/mol. if you were to calculate the number of moles in 23.4 g of cacl2, which example shows the correct way to set up the calculation

Which of these particles is the smallest? A. an atom B. a nucleus C. a proton D. an electron

What type of reaction is sodium reacting with chlorine

1. If temperature is increased, the number of collisions per second

1. Tonic Bonds are a. Formed when a metal and nonmetal transfer electrons b. Formed when a nonmetal and nonmetal share electrons Formed when a metal forms || bonds with other like atoms d. Formed when noble gases lose electrons

Why does the sun appear to be the brightest star in the sky? A - Its apparent brightness is much greater than other stars. B - It burns more gas, making it brighter than any other star.

What effect does nuclear radiation have on atoms? It splits atoms. It burns atoms. It ionizes atoms.