Which of the following always occurs in a

chemical reaction?

A) a gas is given off.

B) a solid is produced,

C) a new substance is produced.

D) a colour change takes place.

Which of the following represents a physical change? A: Phase changing, B: Atoms rearranging, C: Bonds breaking, D: Bonds forming

Name the alkaline earth metal with the highest ionization energy

Identify the intermolecular forces present in each of these substances ch4 h20 co ch3cl

Explain how water might have two different densities

A molecular biologist measures the mass of cofactor a in an average yeast cell. the mass is 41.5 pg. what is the total mass in micrograms of cofactor a in a yeast colony containing 105 cells? write your answer as a decimal.

How to calculate average concentration

Suppose that you measure a pen to be 10.5 cm long. Convert this to meters.

How are amounts of hydrogen and oxygen gas made from the electrolytic decomposition of water related to the chemical formula of water?

Hydrogen peroxide decomposes to water and oxygen at constant pressure by the following reaction: 2H2O2 (l) → 2H2O (l) + O2 (g) ΔH = - 196 kJ Calculate the value of q (kJ) in this exothermic reaction when 3.

What is the concentration of hydronium in each of the following cases: [OH-] = 10-12 M? [OH-] = 10-2 M?