Which of the following words best describe scientists current knowledge about the universe

a) eternal

b) static

c) unpredictable

d) changing

Dmitri Mendeleev's periodic law states that the chemical and physical properties repeat themselves in groups of A. 4 B. 8 C. 12 D. 16

As the number of effective collisions between reacting particles increases the rate of reaction

What is the strongest type of van der Waals force that exists between molecules of ammonia, NH3?

17. Is sodium hydroxide (NaOH) an acid or base?

The ideal gas law equation is PV = nRT. If n, R, and T are kept constant, what happens to the volume if pressure is increased? A) The volume increases B) The volume decreases C) The volume remains unchanged D) The temperature rises

How many protons and electrons does 0^2 - have?

How many ions form when 39 grams of calcium fluoride are added to excess water? a. 0.50 mol b. 1.0 mol c. 1.5 mol d. 3.0 mol

Which term specifically describes small chunks of rocks and debris in space that travel through the Earth's atmosphere and hit its surface? meteorites, meteoroids, meteors, meteorides

What is a covalent bond?

Which statement describes how the binary ionic compound CaCl2 is named? The nonmetal is named first, and the ending is replaced with - ide. The metal is named first, and the ending is replaced with - ide.