Chemistry 111 Unit 1

Elements are substances composed of

only one type of atom

number of elements on the periodic table

118

number of naturally occurring elements on the periodic table

90

elements for 90% of Earth’s crust composition

oxygen, silicon, aluminum, iron and calcium

elements for human body

hydrogen, oxygen, carbon, nitrogen

2 or more atoms joined together chemically

molecule

2 or more atoms of different elements bonded

compounds

what cannot be separated by physical means (heating, filtration)

pure substances

How are physical states of matter interconverted? (solid, liquid, gas)

addition or removal of energy

property of density

physicalp

property of melting point, boiling point

physical

property of evaporation, condensation

physical

property of dissolving

physical

reactivity with other compounds/molecules is a _______ property

chemical

2 or more substances in variable amounts that have not reacted chemically

mixtures

mixtures can be

homogeneous or heterogeneous

formula for kelvin

K = C + 273.15

formula for celsius

C = 5/9(F-32)

formula for fahrenheit

(9/5)(C)+32