A radioactive sample has a half life of 1500 years. A sealed tube containing 1g of the sample will contain after 3000years.

(A) 1 g of the sample

(B) 0.5 g of the sample

(C) 0.25 g of the sample

(D) 0.00 g of the sample

2) 800mm of Hg to Kpa

Which Statement describes the relationship between temperature and pressure of a gas?

All the water on Earth and in its atmosphere is called the?

Which of the following steps can be used to identify a single replacement reaction A) check whether the products are salt and water. B) check whether the reactants are an acid and a base. C) check if the irons of two compounds exchange places.

Why is this reaction considered to be exothermic? a Because energy difference A is greater than energy difference C. b Because energy difference A and energy difference C are about equal.

Which one doesnt belong in the list below? A. a meter B. one liter C. One centimeter D. one kilometer

Which elements did curies discover

When rubidium metal is exposed to air, two atoms of rubidium, Rb, combine with one atom of oxygen. If 1.98 grams of rubidium is exposed to air, what will be the mass of the product in grams

Fission reactions can get of of control without what taking place?

In which main energy level does the 's' sublevel first appear? K (first main energy level) L (second main energy level) M (third main energy level) N (fourth main energy level)