What is the chemical symbol for lead?

A. L

B. K

C. Le

D. Pb

What creates the Van Allen belts? a. Earth's aurora borealis b. Earth's gravity c. Earth's magnetosphere d. Earth's mantle convection.

A compound has a percent composition of 24.74% potassium (molar mass = 39.10 g/mol), 34.76% manganese (molar mass = 54.94 g/mol), and 40.50% oxygen (molar mass = 16.00 g/mol).

Which chemical change causes a cake to rise? formation of a precipitate production of a gas change in state change in color

What is an indication a chemical reaction has occurred? A.) Formation of gas B.) Boiling of a substance C.) Melting of a substance D.) Freezing of a substance

For beta radiation, what stops its penetrating abilities? aluminum a piece of paper skin thin fabric

For an experiment, a biology student makes 1 liter of a solution containing the following substances, which are shown in the table below.

If 1.0 mole of CH4 and 2.0 moles of Cl2 are used in the reaction CH4 + 4Cl2 = > CCl4 + 4HCl then which of these statements is TRUE? A. All of the CH4 will be used up. B. The theoretical yield of CCl4 is 1.0 mole. C. Some Cl2 will be left over. D.

Why do humans primarily form communities? A. To analyze group behavior B. To meet the needs of groups and individuals C. To preserve language and culture D. To make and follow codes of conduct

Which of the following is fact-based science rather than part of a belief system a. astrology b. paranormal investigation c. chemistry d. philosophy e. cultural rituals

Meanders form when a river flows across bedrock? true or false