CHM-101 Exam 1

Tera

T

Giga

G

Mega

M

Kilo

k

Deci

d

Centi

c

Milli

m

Micro

μ

Nano

n

Pico

p

The Great Mighty King Henry Died By Drinking Chunky Milk

Tera, Giga, Mega, Kilo, Hecto, Deca, Base Unit, Deci, Centi, Milli.

Prefixes in order

1. Tera (T)

2. Giga (G)

3. Mega (M)

4. Kilo (k)

5. Base Unit

6. Deci (d)

7. Centi ( c )

8. Milli (m)

9. Micro (μ)

10. Nano (n)

11. Pico (p)

Density Equation

Density = mass / volume

Which is more dense, objects that sink or float?

Objects that sink

What is the density of water?

1.00

What is the unit of measure for density for solids, liquids, and gases?

1. Solids = g / mL

2. Liquids = g / mL

3. Gases = g / mL

What are the steps of the scientific method?

1. Observation (collect info)

2. Question (Ask a question related to observation)

3. Hypothesis (prediction)

4. Experiment (test hypothesis)

5. Analysis (looking at data/relationships and trends)

6. Conclusion (make a judgement)

Exact Number

-Not measured

-Found by counting

-No level of uncertainty

-Do not effect number of sig figs

-Ex. 8 cookies, 1 kg = 1000 g

How do you do sig figs in multiplication/division?

Round to the same number of sig figs as the measurement with the FEWEST sig figs

How do you do sig figs in addition/subtraction?

Round to the same number of decimal places as the measurement with the fewest decimal places

Measured Numbers

-Need tool to obtain that number

-Ex. when you measure height, weight, temperature

Scientific notation for 400,000

400,000 = 4 × 10^5

-bigger to smaller = positive exponent

How many sig figs are in 0.0004?

One

What is density?

-Compares the mass of an object to its volume

-Density = mass / volume

What are the 4 ways to find volume?

1. Given

2. Vobject = L x W x H

3. Vobject = pi x radius squared x h

4. Vobject = Vf - Vi

   1. H2O displacement

   2. Vf = final volume

   3. Vi = intital volume

Know the power of 10 associated with each prefix

1. Tera = 10^12

2. Giga = 10^9

3. Mega = 10^6

4. kilo = 10³

5. Base unit = 10^0

6. Deci = 10^-1

7. Centi = 10^-2

8. Milli = 10^-3

9. Micro = 10^-6

10. Nano = 10^-9

11. Pico = 10^-12

Specific Gravity Definition

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

-Is a unitless quantity

What is the unit for density?

g/mL

What is the equation for specific gravity?

Specific gravity = density of sample / density of water (1.00 g/mL)

What is matter?

-The material that makes up all things

-Anything that has mass and occupies space

-Classified into:

1. Pure substances

2. Mixtures

What can matter be classified into?

1. Pure substances

2. Mixtures

What is a pure substance?

-Has a fixed or definite composition

-Has the same makeup / composition every time you encounter it

-An Element that is composed of one type of atom (item from the periodic table)

-A Compound that is composed of two or more elements always combined in the same proportion

• Ex. H2O

What is a mixture?

-Two or more different substances that are physically mixed but not chemically combined (no bond)

-Composition can vary

-Can be separated by physical methods

-Can be classified into:

1. Homogeneous mixtures

2. Heterogeneous mixtures

What is a homogeneous mixture?

-The composition is uniform throughout

-Different parts of the mixture are not visible

-Ex. first sip of soda should be the same

What is a heterogeneous mixture?

-Composition varies from one part of the mixture to another

-Different parts of the mixture are visible

-Not uniform distribution

-Ex. tossed salad, can see the different parts of the salad

What is an atom?

-Smallest particle of an element that retains the characteristics of an element

-Ex. single particle of sodium

What is an element?

-Pure substances that cannot be separated into simpler substances by ordinary lab processes

-The building blocks of matter

-Ex. the elements of the periodic table

What are molecules and compounds?

-When elements combine to form larger units

-Either a molecule or compound

What is a molecule?

-Combined elements

-Smallest unit of two or more atoms held together by a covalent bond

-Referring to quantity

- O = Oxygen

- O2 = molecule of oxygen

-CH3OH = molecule of methanol

What is a compound?

-Pure substances consisting of two or more types of elements, which have a definite composition

-Talking about the type of substance

-Ex. methanol is a type of covalent compound

Molecules and compounds

All molecules are not compounds. All compounds are molecules.

What is solid?

1. Have a definite shape

2. Have a definite volume

3. Particles that are close together in a fixed arrangement

4. Particles that move very slowly

   1. Have a slow energy level

   2. Forms very rigid connections w/ one atom to another

      1. Fixed arrangement

      2. Keeps atoms in place, gives defined shape and volume

What is a liquid?

1. Has a indefinite shape

2. Has a definite volume

3. The same shape as their container

4. Particles that move slowly

5. A liquid has a definite volume but takes the shape of its container

What is a gas?

1. Has an indefinite shape

2. Has an indefinite volume

3. The same shape and volume as their container

4. Particles that are far apart

5. Particles that mover very fast

6. A gas that takes the shape and volume of its container

What is a physical property?

1. Shape

2. Physical state

3. Boiling and freezing points

4. Density

5. color of the substance

What is a physical change?

1. Change in the state (ex. ice)

2. Change in the physical shape

-Ex. evaporation, ice, cutting something

What is a chemical property?

-Describe the ability of a substance to:

1. Interact w/ other substances

2. Change into a new substance

What is a chemical change?

-The original substance is turned into one or more NEW substances (with a totally NEW composition) with a new chemical and physical properties

What is a group in the periodic table?

Vertical column

What is a period in the periodic table?

Horizontal rows

What groups on the periodic table are representative elements?

Groups 1A-8A

What groups on the periodic table are transitional elements?

Groups 3B-12B

What is group 1A on the periodic table?

Alkaline metals

-Highly reactive

-(+1 charge when the ionize)

What is group 2A on the periodic table?

Alkaline earth metals

-Not as reactive as 1A

-(+2 charge when the ionize)

What is group 7A on the periodic table?

Halogens

-Prevalent in body

What is group 8A on the periodic table?

-Noble gases

-Very unreactive

What is a metal and its characteristics?

1. Shiny and ductile (shapeable)

2. Are good conductors of heat and electricity

What is a nonmetal and its characteristics?

-Are dull, brittle, and poor conductors

-Are good insulators

What are metalloids and its characteristics?

-Are better conductors than nonmetals but not as good as metals

-Are used as semiconductors and insulators

How do you calculate atomic number?

# of protons

How do you calculate mass number?

# of protons + # of neutrons

How do you calculate the # of neutrons?

mass number - atomic number

What is an isoptope?

-Atoms of the same element

-Have different mass numbers

-Same number of protons, but different numbers of neutrons

-Can be distinguished by their atomic symbols

-Ex. magnesium-24

What is atomic mass and how do you calculate it?

-The average of all masses of stable isotopes of that element

-Calculate using the formula, the add all together

Electromagnetic Radiation

-Energy particles that move as waves of energy

-Distance between the peaks is called the wavelength

-High-energy radiation = shorter wavelengths

-Low-energy radiation = longer wavelengths

Atomic Spectrum

-When light from a heated element passes through a prism, it separates into distinct lines of color separated by dark areas called an atomic spectrum

-Each element has its own unique atomic spectrum

How are electrons grouped?

-In energy levels (principle quantum number)

-The lines in an atomic spectrum are associated with the changes in energies of the electrons

-Energy levels are assigned principal quantum #’s

-Electrons with the same energy are grouped in the same energy level

-Electron arrangement shows how the electrons are distributed in each level/shell

-For the first 20 elements, the order is 2,8,8,2

What is the electron arrangement for the first 20 elements?

2,8,8,2

What are valence electrons?

-The # of electrons in the outermost energy level

-Ex. 2,8,3 (3 valence electrons)

What is the group number?

-The number of valence electrons for the representative elements

What is atomic size?

-The distance from outermost of orbit to other side

-Diameter

-Atoms get bigger as you move:

• Down

• To the left

What is ionization energy?

-The required energy to remove one of the outermost electrons (valence electrons)

-As the distance from the nucleus to the valence electrons increases, the ionization energy decreases

-The smaller the atom —> the bigger the ionization energy

Which has a bigger ionization energy, a bigger atom or a smaller atom?

A smaller atom

What is metallic character?

-How easy it is to lose valence electrons

-Pretty much opposite of ionization energy

-More prevalent in metals on the left side of the periodic table

-Less for nonmetals on the right side of the periodic table, which do not lose electrons easily

What is the relationship between ionization energy and metallic character?

↑ ionization energy = ↓ metallic character

↓ ionization energy = ↑ metallic character

What is the charge of an atom?

-Neutral

-Protons = electrons

Does neutral mean stable?

-No

-They want to become noble gases

How do atoms stabilize themselves?

-In a process called ionization

-Atoms will lose, gain, or share electrons to achieve an electron arrangement that is like that of their nearest noble gas (8a)

-Often referred to as the octet rule since the noble gases have 8 valence electrons

what are the two types of bonds that are formed when atoms ionize?

1. Ionic bonds

2. Covalent bonds

What is an ionic bond?

-The transfer of electrons to obtain a noble gas arrangement

-METAL + NONMETAL

Do metals and nonmetals lose/gain electrons when they ionize?

-Metals = lose electrons

-Nonmetals = gain electrons

What is a covalent bond?

-Nonmetals share electrons to achieve a noble gas arrangement

-NONMETAL + NONMETAL

Do metals gain or lose electrons?

-Lose electrons

-Become CATIONS

-In an ionic bond

Do nonmetals gain or lose elctrons?

-Gain electrons

-Become ANIONS

-Nonmetals = always negative

What is a cation?

-Nonmetal

-You gain electrons to have the same number of electrons as a noble gas

What is a anion?

-Metal

-You lose electrons to have the same number of electrons as a noble gas

3 types of ions?

1. Representative metals and nonmetals

   1. Ions that form from representative elements

   2. A group elements

   3. Charge can be determined from position on the periodic table

2. Transition metals

   1. Positive charge

   2. Charge can fluctuate

3. Polyatomic ions

   1. Ions that form from may atoms

   2. Group of atoms that ionize as a group

How do you name cations?

1. Name the element

2. Tack on the word “ion” at the end

3. Ex. calcium = calcium ion

How do you name anions?

1. Name the element

2. Lose the ending and at “-ide” suffix

3. Tack on the word ion at the end

4. Ex. sulfure = sulfide ion

How do you know what charge transition metals (B group) have?

-Since the charge can fluctuate, you need roman numerals

What are the 3 metals in the B group that do not transition and do not need a roman numeral?

1. Zn²⁺

2. Cd²⁺

3. Ag⁺

-Treat like a group A metal

What metals in group A transition and need a roman numeral?

1. Sn (tin)

2. Sb (antimony)

3. Ti (thallium)

4. Pb (lead)

5. Bi (bismuth)

What are the properties of ionic compounds?

-Consist of positive and negative ions

-(+) and (-) seek each other out, need each other to even out

-Common traits:

1. Have high melting/boiling points

   1. Means substance is very stable

2. Are solid at room temperature

How do you write formulas for ionic compounds?

-Total positive charge = total negative charge

-Lowest common multiple

What is a covalent compound?

-Two nonmetals share electrons and form a covalent bond

-Valence electrons are shared in order to acheive stability

-Ex. CO, CO2, CO3

Which element is listed first in a ionic compound?

-The cation is listed first

-Metal than nonmetal

Which element is listed first in an ionic compound?

-The element with the lowest electronegativity

-Values are listen on back of periodic table

—Electronegativity increases as you go up and to the right

How do you name covalent compounds?

1. First nonmetal is the element name normally

   1. except if there is more than one, then you need a prefix

2. Second nonmetal is the first syllable plus -ide

   1. If a subscript is used, you need a prefix

What are the prefixes used in covalent compounds?

• Mono = 1

• Di = 2

• Tri = 3

• Tetra = 4

• Penta = 5

• Hexa = 6

• Hepta = 7

• Octa = 8

• Nona = 9

• Deca = 10

What letters can/cannot go together when naming covalent compounds?

• oo

• oa

• aa

-Drop the first vowel