How long have people studied chemistry?

How many valence electrons does an atom of any halogen have?

What element has 3 electrons in its 5d sublevel? A. Nd B. Nb C. Ta D. U

Which statement best describes two events that occur at a convergent boundary where one plate moves under another A. Frequent earthquakes may occur volcanic activity may be common B.

What is the mass of sodium chloride used to make 100mls of a 1.0M sodium chloride solution?

Identify the precipitate (if any) that forms when KOH and Cu (NO3) 2 are mixed

Will an object with a density of 0.97 g/ml float or sink in water

Which subatomic particle contributes least to the mass of the atom? which subatomic particle contributes least to the mass of the atom? neutron electron proton all of these contribute equally?

2H2S (g) 2H2 (g) + S2 (g) Kc = 1.67 * 10 ^-7 at 800 C A 0.500 L reaction vessel initially contains 0.0125 mol of H2S at 800 C. Find the equilibrium concentrations of H2 and S2.

An atom has an atomic number of 9 a mass number of 19 and an electron configuration of 2-6-1 explain why the number of electrons in the second and third shells shows that this is in an excited state

How can a chemical reaction be sped up? Pack in more of the reactant to increase the_.