What type of nuclear reaction do thermonuclear weapons rely on? a. fusion c. both fusion and fission b. fission d. None of the above

Alkanes are saturated organic molecules that contain only carbon and hydrogen atoms connected through single bonds.

Which of the following best explains why most chemical reactions proceed more quickly when the concentrations of reactants are increased? a. The increased concentration increases the number of collisions between molecules. b.

Frieda makes a pyramid of oranges for a display at the grocery store. A few minutes later, Corwin bumps into the display and the oranges spill down. Which change of state does the motion of the oranges most closely model?

A balloon containing helium gas expands from 230 mL to 860 mL as more helium is added. What was the initial quantity of helium present if the expanded balloon contains 3.

Which of the following produces a chemical change?

What is the relationship between chemical equilibrium and the rates of forward and reverse reaction

What is the valence of Fluorine

When liquid helium is exposed to room temperature, it forms a gas. Which best explains why this happens? The liquid helium absorbs energy from the air in the room. The particles in the air absorb the energy of the liquid helium.

Why was Bohr's model considered more accurate than Dalton's model?

Select the statements that correctly describe a buffer. 1) The pH of a buffer solution does not change significantly when any amount of a strong acid is added. 2) A buffer is generally made up of a weak acid and its conjugate base.