The half-life of a certain element is 100 days. How many half-lives will it be before only one-fourth of this element remains? 4

50

25

2

Convert 12.0 kilograms into grams. Convert 4.3 meters into centimeters. Convert 900 milligrams into grams. Convert. 7 millimeters into centimeters.

The last column of the periodic table contains the noble gases, elements that do not easily form chemical bonds.

What is a mixture of small pieces of rock with decayed plants and animals

Why is MnO2 added to the decomposition of H2O2 reaction? A. to increase potential energy B. to increase the net energy of the reaction C. to decrease the activation energy D. to decrease the reaction progress

Calculate the hydronium ion and hydroxide ion concentrations in human blood at 25oc

Compare and contrast the two kinds of chemical bonds (ionic and covalent)

If a thin and a thick wire are otherwise identical, what property is lower for the thicker wire? 1. current 2. static charge 3. resistance 4. voltage

Which set of numbers gives the correct possible values of l for n = 2?

Light from the sun is absorbed by the ground and converted to what?

What contains paired statements that can be used to identify orgainisms