What is 50% of 90?

An atom of 40 18 Ar has a nucleus that contains a total of a) 18 electrons b) 18 protons c) 18 neutrons d) 18 nucleons

The highest occupied s and p sublevels are partially filled

What unit is used for measurement atomic mass

1. The creatures preserved in the Burgess Shale fossils are most closely related to modern a. reptiles. b. mammals. c. fish. d. insects.

What is the ph of a 0.21 m solution of pyridinium chloride (c5h5nh+cl-) ? (kb for pyridine is 1.5 * 10-9.) answer in units of ph?

What are explosives made up of

For the equilibrium reaction 2NH3 (g) + 22 kJ ↔ N2 (g) + 3H2 (g), which of the following changes would result in the formation of more N2 and H2 at equilibrium?

When a chemical reaction occurs, atoms rearrange to form new compounds, but no new atoms are created nor are any destroyed. this concept is called conservation of mass.

The elements on the Periodic Table are arranged in order of increasing (1) atomic mass (2) atomic number (3) first ionization energy (4) selected oxidation state

How many atoms in 6.2 moles of aluminum