What atom has a nucleus that contains 13 protons and 14 neutrons

Which best explains what happens when an electron moves from an excited state to the ground state? A) The electron absorbs energy as it moves to a lower energy level. B) The electron absorbs energy as it moves to a higher energy level.

What partial pressure of hydrogen gas is required in order for 0.00100 g of the gas to dissolve in 17.6 ml of pure water? the henry's law constant for hydrogen gas is 7.8 * 10-4 m atm-1?

The ionization energies of several of the Group 1 elements in the periodic table are shown in the table below

How come Sulfur have more than 8 electrons in its valence?

What experiment did j. j. thomson do?

Examples of chemical and physical changes

Is when hot parts of the earth rise as cooler parts sink due to differences in density.

Distinguish between the structures of arteries, capillaries, and venies. what is the function of each.

Which phase of matter has a fixed volume but variable shape

Given 10.8 grams of substance Y, if the substance absorbs 231 kilojoules of energy and the specific heat of the substance is 6.55 J/g·°C, what is the change in temperature?