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?

Is a polar molecule an ionic or covalent compound?

A 100.5 ml intraveneous (iv) solution contains 5.10 g glucose (c6h12o6). what is the molarity of this solution?

Where will you find maximum rate of evaporation - ocean, pond or an aquarium? Give reason to support your answer.

Which sample of matter is a mixture? (1) Br2 (ℓ) (3) KBr (s) (2) K (s) (4) KBr (aq)

How many phosphoester (phosphate ester) and phosphoanhydride bonds are in adenosine and adenosine triphosphate (atp) ?

Every water molecule has two hydrogen atoms bonded at one oxygen atom. This fact supports the concept that elements in a compound are

What is the mass of 9 atom (s) of copper in grams?

Andy has two samples of liquids. Sample A has pH of 4, and sample B has a pH of 6. what can Andy conclude about these two samples? Sample A is a neutral b alkali c acidic Sample B is a neutral b alkali c acidic

How does a lone pair contribute to molecular shape? A. It is too small to affect the molecule's shape. B. It takes up space like an "invisible" atom. C. It forces the molecule into a tetrahedral shape. D. It lets the bonding pairs spread out more.

The are of a rectangle is 12 in^2. what is the area in cm^2. there are 2.54cm in an inch.