How much of a sample remains after five half-lives have occurred?

A cube of gold-colored metal with a volume of 54 ml has a mass of 980 grams. the density of pure gold is 19.3g/ml. Is the metal pure gold? why?

Which solution is a buffer? which solution is a buffer? a solution that is 0.100 m in hno3 and 0.100 m in nano3 a solution that is 0.100 m in hno2 and 0.100 m in nano2 a solution that is 0.100 m in hno2 and 0.100 m in hcl a solution that is 0.

What is the concentration of the acid in this titration? 1.2 m 2.4 m 1.95 m 0.98 m 1.98 m?

Jill is studying the temperature output of an ammonium chloride hand warmer with a calorimeter. What change should she expect to see in the temperature of the water over time? A) The water will continue to heat up as the experiment progresses.

For the reaction A + B - ⇀ ↽ - C + D, assume that the standard change in free energy has a positive value. Changing the conditions of the reaction can alter the value of the change in free energy (Δ G).

According to the following reaction, how many grams of hydrogen peroxide ( H 2 O 2 ) are necessary to form 0.182 moles oxygen gas? hydrogen peroxide ( H 2 O 2 ) (aq) → water (l) + oxygen (g)

Using the bohr model describe the changes in electrons energy and electron location when an atom changes from the ground state to an excited state.

Sally is making a model of gold for her chemistry class. She has foam balls for the protons, neutrons, and electrons. She has added 70 protons to her model so far. How many more protons does she need to add to complete her neutral atom of gold?

How many electrons are in an atoms of germanium

What is the lewis structure of N2O3?