Chem Midterm Practice

Sublimation

Solid —> gas

Deposition

Gas —> solid

Element

Pure substance - only one type of atom

Compound

Formed when two or more different elements are chemically bonded together

pure substance

made up of only the same element or the same compound

mixture

two or more substances that are physically combined but not chemically bonded

homogeneous mixture (solutions)

have a uniform composition throughout

heterogeneous mixtures

have a non-uniform composition

rules for adding or subtracting (sig figs)

result should have same number of decimal places as the number with the least amount of decimal places

rules for multiplying or dividing (sig figs)

result should have the same number of significant digits as the number with the least number of significant digits