Element A has a half-life of 10 days. A scientist measures out 200 g of this substance. After 30 days has passed, the scientist reexamines the sample.

How much Element A will remain in the sample?

50 g

25 g

12.5 g

100 g

What percentage of radioactive substance remains after two half-lives

According the recent research, ice skaters are able to glide smoothly across the ice because

How does a newtonian fluid difference from a nin newtonian fluid

A piece of sodium metal when thrown in water catches fire. give reason

a powder drink sells for 299 per can each can makes 8 liters of drink what will be the cost of making 35 L of drink

Who's theory states that atoms are made up of empty space with electrons around a positively charged mass?

O3 (g) + NO (g) O2 (g) + NO2 (g) Write the equalibrium expression

You are given 10.00 mL of a solution of an unknown acid. The pH of this solution is exactly 2.36. You determine that the concentration of the unknown acid was 0.3535 M. You also determined that the acid was monoprotic (HA).

What mass of copper is consumed in the reaction with hydrochloric acid if 10.0 g of gas is collected?

How does the movement of molecules inside a solid block of iron change as the iron is heated? The molecules move faster. The molecules move slower. The molecules stop moving completely. The molecules move in the same way at all temperatures.