Which of these pairs of elements have the same number of valence electrons?

phosphorus (P) and chlorine (Cl)

berylium (Be) and calcium (Ca)

chlorine (Cl) and helium (He)

oxygen (O) and carbon (C)

In the correctly balanced equation, what are the coefficients for H2, Cl2, and HCl (respectively) ? ___H2 + ___Cl2 → ___HCl 1,1,1 2,2,1 1,1,2 2,1,2

The mass of an astronaut in space will be: c the same as on earth greater than on earth less than on earth

Which is a product in the following chemical reaction? CH4 + 2O2 → CO2 + 2H2O CH4 H4 H2O O2

1. What conditions cause deviations from the "ideal" gas? Select all that apply. low temperatures high temperatures low pressure high pressure 2. What conditions cause deviations from the "ideal" gas? Select all that apply.

Subtractive color mixing involves mixing lights, as seen in theaters.

Convert 1.67 x10^24 atoms of carbon to moles of carbon

The knowledge of chemistry not important in one of the following? A, in agriculture B, in Geology C, in medicine D, none

Which is the balanced equation for: Al2O3 + Fe - Fe3O4 + AL

Why are lab apparatus made of ceramics

The volume of oxygen required for complete combustionof a mixture of 5 cm3 of ch4 and5 cm3 c2h4