4. Which statement is true about alkali metals?

A. Some of them explode when exposed to water.

B. They are not conductors of heat or electricity.

C. They are not very reactive.

D. They are in group 18 of the periodic table

An equilibrium mixture of the three gases in a 1.00 L flask at 698 K contains 0.323 M HI, 4.34E-2 M H2 and 4.34E-2 M I2. What will be the concentrations of the three gases once equilibrium has been reestablished, if 0.

A ball-and-stick model of a molecule provides much the same information as a

Classify each of the following as an element, a compound, a homogeneous mixture, or a heterogeneous mixture: (a) seawater, (b) helium gas, (c) sodium chloride (salt), (d) a bottle of soft drink, (e) a milkshake, (f) air in a bottle, (g) concrete.

Why science can answer some questions, but not others

What is a chemical equation?

You want to create 14.0 g of copper to meld into a piece of jewelry. You know that when copper (II) chloride reacts with aluminum, copper is a product. How much aluminum would you need to start your reaction with to get 14.

What happens to electronegativity values when moving from left to right across the period in the periodic table

A 27.40 g sample of liquid mercury is initially at 158.30°C. If the sample is heated at constant pressure ( = 1 atm), kJ of energy are needed to raise the temperature of the sample to 376.20°C. How much energy in kJ is required?

When a sample of gas is cooled, it condenses into a liquid. In which of the following ways do the molecules of the original gas sample compare with the molecules of the liquid? a. The molecules weigh less as a gas than they do as a liquid. b.

In a group 1 analysis, a student obtained a precipitate containing both AgCl and PbCh. Which of the following reagents would enable separation of AgCl (s) from PbCl (s) ? O Hys 0 Na2CO3 o KOH O NH3 O