Which of the following pairs of elements is most likely to form an ionic bond?

A.

calcium and fluorine

B.

carbon and oxygen

C.

phosphorus and chlorine

D.

nitrogen and oxygen

If the solvent front is 68 mm and the ring front of an unknown is 48mm from the original spot, what is the rf value?

Cl is highly reactive. We know NaCl to A: have similar properties to Cl B: be highly reactive C:have completely different properties D: take on some of the properties of Cl

The temperature of 75 mL of gas is decreased from 450 K to 150 K while the pressure is held constant. What is the new volume of the gas? A 25 ml B. 225 mL C. 300 mL D. 375 mL

The amount of water vapor in the air is referred to as what? A. air pressure B. humidity C. temperature D. salinity

According to dalton's atomic theory, when elements react, their atoms combine in

The organic compound aldehyde contains which functional group? amide carbonyl carboxyl hydroxyl

Which astronomer supported the belief that earth was at the center of the universe while all other planets and celestial objects orbited around it

When a solution of LiC2H3O2 reacts with a solution of MgSO4, what is the net ionic equation? No reaction Mg+2 (aq) + C2H3O2 - (aq) → Mg (C2H3O2) 2 (s) Mg+2 (aq) + 2C2H3O2 - (aq) → Mg (C2H3O2) 2 (s) 2Li + (aq) + SO4-2 (aq) → Li2SO4 (s)

What are the relations between Electrochemistry and Cancer?

Which of the following are sources of low-level radiation? A) medical X-rays B) nuclear weapons testing C) buring of fossil fuels D) all of the above E) a and c only