Suppose a laboratory has a 38 g sample of polonium-210. the half-life of polonium-210 is about 138 days.

a. how many half-lives of polonium-210 occur in 1104 days?

b. how much polonium is in the sample 1104 days later?

A firework exploding is an example of a physical change chemical change phase change nuclear change

Give TWO examples of energy conversion that produces unwanted forms of energy.

In the past 100 years the average temperature in the United States has increased

9. Let's say, you need to make 2.00 L of 0.05 M copper (II) nitrate solution. How many grams of copper (II) nitrate will you require?

In a test of an automobile engine 1.00 L of octane (702 g) is burned, but only 1.84 kg of carbon dioxide is produced. What is the percentage yield of carbon?

Which of the following has the highest critical temperature? H2 N2 NH3 H2O

Are there any good tips for organic chemistry reactions?

Why is there such a vast climate difference in these two areas of the grand canyon the inner canyon and north rim?

If an objects volume decreases but the mass stays the same why

47 When the pH of an aqueous solution is changed from 1 to 2, the concentration of hydronium ions in the solution is (1) decreased by a factor of 2 (2) decreased by a factor of 10 (3) increased by a factor of 2 (4) increased by a factor or 10