CHEM 105 Exam 1 MCC

Chemistry

the study of the composition, structure, properties, and reactions of matter. It happens around you every day!

chemical

a substance that always has the same composition and properties wherever it is found.

Scientific Method order

Observations, Hypothesis, Experiments, Conclusion

64,000 in Scientific Notation

6.4 x 10^4

0.021 in Scientific Notation

2.1 x 10^-2

43.023 g in Scientific Notation

4.3023 x 10^1 g

1 kilometer =

1000 meters

1 kiloliter =

1000 liters

1 kilogram =

1000 grams

1 cm =

10 mm

1 m =

100 cm

1 L =

10 dL or 1000mL

1 dL =

100 mL

1 mL =

1000 μL (mcL)

Density

the ratio of the mass of an object to its volume.

Calculate Density

mass/volume

Specific gravity

the relationship between the density of a substance and the density of water.

Matter

anything that has mass and occupies space.

Energy

the ability to do work.

Elements

the simplest type of a pure substance, is composed only of one type of material such as silver, aluminum, or iron.

Compounds

consist of atoms of two or more elements that are chemically combined in the same proportion.

Pure substances

elements and compounds

Mixtures

contain two or more different substances that are physically mixed but not chemically combined. Homogeneous and Heterogenous

Homogeneous mixtures

also known as solutions, have a uniform composition throughout the sample. We cannot see the individual components, which appear as one state.

Heterogenous mixtures

do not have a uniform composition throughout the sample. The components appear as separate regions.

Chemical properties

he ability of a substance to change into a new substance.

Chemical changes

occur when the original substance is converted into one or more new substances which have new physical and chemical properties

Know conversion from Fahrenheit to Celsius and Celsius to Kelvin

I know it

types of energy

kinetic and potential

Kinetic energy

is the energy in motion.

Potential energy

determined by the position of an object or its chemical composition.

specific heat

the amount of heat needed to raise the temperature of exactly 1 g of a substance by exactly 1 °C.

Sublimation

when the particles on the surface of a solid change directly to a gas without going through the liquid state. There is no change in temperature.

Deposition

when gas particles change directly to a solid.

know periodic table

I know the table

Dalton's Atomic Theory #1

All matter is made of up tiny particles called atoms.

Dalton's Atomic Theory #2

All atoms of a given element are the same and different fromatoms of other elements.

Dalton's Atomic Theory #3

Atoms of two or more different elements combine to form compounds. A particular compound is always made up of the same kinds of atoms and always has the same number of each kind of atom.

Dalton's Atomic Theory #4

A chemical reaction involves the rearrangement, separation, or combination of atoms. Atoms are neither created nor destroyed during a chemical reaction.

found outside the nucleus

electron

has a positive charge

proton

has mass but no charge

neutron (think neutral)

atomic number

number of protons which is the same # as electrons

Mass Number

number of protons + the number of neutrons

mass number - atomic number =

electrons

Isotopes

atoms of the same element that have the same atomic number but different numbers of neutrons.

atomic mass

Calculated based on the weighted average of all naturally occurring isotopes. Found below symbol

electron arrangements

atomic # going in form of 2,8,8,2

Si atomic number = 14

Find electron arrangements

2,8,4

Valence electrons

electrons in the outermost energy level. Found with group #

Lewis symbol

way to represent the valence electrons of an element

Ionization energy (opposite direction as metallic and atomic)

the energy required to remove one of the outermost electrons. decrease going down a group and increase going across a period from left to right.

metallic character (same direction as atomic)

loses valence electrons easily. increases going down a group and decreases going from left to right across a period.

Atomic size (same direction as metallic)

increases going down a group but decreases going from left to right across a period.