Quiz 2 and 3 Math/chem review

Question 1

Accuracy is:

Answer 1

The agreement between experimental data and the “true” value

Question 2

Precision is:

Answer 2

The agreement between replicate measurements.

Question 3

T/F: One can be precise without being accurate.

Answer 3

True

Question 4

Density = _____/______

Answer 4

mass/volume

Question 5

Specific Gravity=

Answer 5

ratio between an object’s density and the density of water.

A value >1 is more dense than water, value <1 is less dense than water.

Question 6

Chemistry is defined as

Answer 6

the study of matter and it’s changes

Question 7

Matter is

Answer 7

anything that has mass and occupies space

Question 8

What is considered the building blocks of matter?

Answer 8

Atoms

Question 9

Name the 3 parts of an atom

Answer 9

Protons, neutrons and electrons

Question 10

Do Protons have a + or - charge?

Protons mass =?

Answer 10

Positive + charge

Mass = 1 atomic mass unit (amu)=1.66 x 10 to the -27

Question 11

The atomic number (Z) identifies the atom by the number of what?

Answer 11

Protons

Question 12

What is the charge of a Neutron?

Answer 12

Neutral, no charge.

Question 13

Electrons have what charge? and have a mass of?

Answer 13

Negative

negligible amount of mass.

Question 14

Cations= + or -

Answer 14

+ charged ions

Question 15

Anions = + or -

Answer 15

• charged ions

Question 16

compounds contain

Answer 16

more than one kind of atom in a fixed ration by mass.

ex. CO2 or NaCl

Question 17

Molecules are:

Answer 17

groups of atoms chemically bonded together into a discrete unit by covalent bonds. The have a neutral charge.

Question 18

Ionic compounds:

Answer 18

Contain both + and - charged ions with no identifiable units. Attracted by charge and are NOT molecules.

Question 19

Can a substance be both a molecule and an element?

Answer 19

Yes: O2; neutral charge.

Question 20

ice melting or boiling water is an example of what kind of change?

Answer 20

Physical change. Same substance, different state.

Question 21

combustion is an example of what kind of change?

Answer 21

Chemical change. started out as one substance, became another.

Question 22

_____ properties can be observed and measured w/o changing the chemical makeup

Answer 22

physical

Question 23

intensive properties include_____

Answer 23

color, shape (does not effect amount or volume)

Question 24

extensive properties include___

Answer 24

Amount, size, volume… (magnitude)

Question 25

Chemical property:

Answer 25

describes the type of chemical changes the material tends to undergo. (flammable)

Question 26

Substances are:

Answer 26

Pure materials that cannot be physically separated into simpler components. Chemical and physical properties are uniform throughout.

Question 27

Mixtures are 2 or more pure substances. T/F physical processes can separate the mixture into simpler substances

Answer 27

True

Question 28

Homogenous

Answer 28

Uniform in physical and chemical properties throughout the whole sample. (normal saline)

Question 29

Heterogenous

Answer 29

distince phase boundaries where chemical or phosical properties change. (italian salad dressing or chia seeds in a beverage.)

Question 30

T/F: All atoms have protons and electrons and all contain neutrons except for hydrogen.

Answer 30

True

Question 31

A (atomic Mass number) =Z (atomic number) +N

Is the equation that finds the number of what?

Answer 31

Neutrons

Question 32

T/F Isotopes are the same element with a different number of neutrons.

Answer 32

True; They have the same atomic number, different mass number.

Question 33

Dalton’s Atomic Theory:

1. ____ are the smallest units of substance
2. Compounds are formed by bonding ____ together in a fixed ratio.
3. Chemical reactions do not create, destroy, or change ___ into ___of other elements. Chemical reactions cause ____ to recombine into new substances.

Answer 33

atom or atoms.

Dalton’s flaws:

• Not all atoms of an element are identical isotopes.
• Atoms are comprised of even smaller particulars AND nuclear processes convert atoms of one element into atoms of another.

Question 34

Law of conservation of Mass

Answer 34

components are neither created, nor destroyed. They combine.

Question 35

Law of Definite Proportions

Answer 35

Different samples of a pure compound always contain the same elements in the same proportion by mass.

example: water= 11.2% Hydrogen and 88.8% Oxygen by mass.

Question 36

Law of Multiple Proportions

Answer 36

Some elements can combine to give more than one compound.

ex: carbon burned produces both CO2 and CO.

Question 37

The Periodic Table is organized with rows and vertical groups/families.

The number to protons increases from _____ to _____ (which direction) in the rows.

Answer 37

L to R

Question 38

The Periodic Table is organized with rows and vertical groups/families.

The elements at the end of each row has a full or empty outer shell of electrons? (R side of the table)

Answer 38

Full

Question 39

The Periodic Table is organized with rows and vertical groups/families.

Vertical columns of elements share what similarities?

Answer 39

Similar chemical and physical properties.

Question 40

Elements with nearly full electron shells ___ electrons, anions.

Answer 40

accept

Question 41

Elements with nearly empty electron shells ____ electrons, Cations.

Answer 41

give up or release

Question 42

Characteristics of metals include:

Answer 42

• shiny luster
• ductile (can be drawn out into a wire)
• malleable
• good conductors of heat and electricity
• react to form cations by giving away electrons

Question 43

Characteristics of non-metals include:

Answer 43

• liquids, solids, or gasses
• solids tend to be brittle
• do not conduct
• tend to form anions

Question 44

Characteristics of metalloids

Answer 44

• intermidiates
• shiny luster
• less malleable and ductile than metals
• conduct electricity but not well-semi conductors

Question 45

electrolyte

Answer 45

substance that dissolves in water to give a solution conductivity.