Which of the following determines the identity of an element?

A) atomic number

B) mass number

C) atomic mass

D) overall charge

A. What happens when the two atoms are fairly close?

B) How much hydrogen in Liters was used to make 0.0879 moles of H2O?

An element's atomic number is equal to its number of

What does a strong nuclear force do in an atom? It repels electrons from other electrons. It repels protons from other protons. It attracts protons and neutrons. It attracts protons and electrons.

A sample of sodium reacts completely with 0.497 kg of chlorine, forming 819 g of sodium chloride. what mass of sodium reacted?

What is the concentration of hydronium in each of the following cases: [OH-] = 10-12 M? [OH-] = 10-2 M?

Which statement best explains why elements are matter? An element is a physical substance that has mass and takes up space. Elements are pure substances that cannot be divided chemically. Each element is a pure substance composed of one type of atom.

Which of the following best describes what causes the phases of the moon? The alignment of the sun, Earth, and moon The speed of the moon around the Earth The speed of the Earth around the sun The alignment of the planets

At which temperature would atoms of a He (g) sample have the greatest average kinetic energy? (1) 25°C (3) 273 K (2) 37°C (4) 298 K

In the reaction, HCl + H2O produces H3O + Cl, what is the conjugate acid