Identify each of the following as either a physical change or a chemical change. Explain your answers.

A. a piece of wood is sawed in half.

B. milk turns sour.

C. melted butter solidifies in the refrigerator.

Which of the following is covalent? BeCl2 AlN NaK SO2

Consider this reaction: N2 (g) + O2 (g) = 2NO (g) What will happen if pressure is increased on the system? A There will be a shift toward the products. B There will be a shift toward the reactants. C There will not be a shift. D Keq will increase.

An apparatus consists of a 3 L flask containing nitrogen gas at 17◦C and 822 kPa, joined by a valve to a 10 L flask containing argon gas at 17◦C and 59 kPa. The valve is opened and the gases mix.

What happens to the buoyant force of a submerged submarine when water is taken into its tanks and it dives? It remains unchanged. It increases. It balances the weight. It decreases.

How many molecules are there in 9.34 grams of water

How can you make results of an investigation more reliable?

Cuales son los reactivos y los productos del enlace peptidico?

Chemical changes sometimes produce a gas which you can detect by observing

A nuclear reaction in which two light nuclei combine to form a more massive nucleus is called (1) addition (3) fusion (2) fission (4) substitution

What type of forces affects the speed and direction of motion of an object? A: Balanced forces B: Unbalanced forces C: Equal and opposite forces in the vertical plane D: Equal and opposite forces in the horizontal plane