A force can exist between two charged particles or objects even if they're as small as subatomic particles. between which of these would a repulsive force exist?

a. proton-proton

b. electron-electron

c. neutron-neutron

d. a and b

A student is given two beakers. The first contains a 2M solution of an acid. The second a 2M solution of a base. A) Which has the lowest pH? B) Which has the highest hydronium concentration? C) In which is the water acting as a base?

Martha Stewart does not do her own ironing because she: Select one: a. is not very good at ironing. b. has an absolute advantage in ironing. c. has a comparative advantage in ironing. d. has a comparative advantage in something else.

Which of the following is a reason for creating hybrid plants? yield more crops increase growing season decrease resistance to herbicides reduce amount of manual labor

Use vsepr to predict the electron pair geometry of o2

What's the formula mass for (NH4) 3PO4

The graph below shows how solubility changes with temperature. What is the solubility of Na2HAsO4 at 60°C? 20 g/100 mL of water 46 g/100 mL of water 65 g/100 mL of water 70 g/100 mL of water

Which statement regarding water is true? Energy must be given off in order to break down the crystal lattice of ice to a liquid. Hydrogen bonds are stronger than covalent bonds. Liquid water is less dense than solid water.

Which of the following elements has the fewest valence electrons?. a. beryllium. b. boron. c. carbon. d. lithium

How many molecules are in 4.50 moles of H2O? A. 450 molecules B. 6.02 x 1023 molecules C. 2.71 x 1024 molecules D. 3.00 molecules

A sample of pure calcium fluoride with a mass of 15.0 g contains 7.70 g of calcium. How much calcium is contained in 45.0 g of calcium fluoride