chapter2-4 Exam

Elements

pure substance that contains only one type of material Ex: copper (Cu)

Compounds

contains two or more elements Ex: hydrogen peroxide (H2O2)

Mixtures

two or more substances that are physically mixed not chemically Ex: Na and Cl or Na + Cl

Homogeneous mixtures

the different parts of the mixture are not visible and are uniform throughout Ex: sugar water

Heterogeneous mixtures

the different parts of the mixture are visible Ex: pennies in water or spaghetti

What classification is air

Homogeneous

Is a hot fudge sundae hater or homo

Hetergenous

Solids

have a definite shape, definite volume, particles are close together, particles move very slowly

Liquids

have an indefinite shape but definite volume, particles are close together but mobile, particles move slowly

Gases

have an indefinite shape, an indefinite volume, the same shape and volume as their container, particles that are far apart, particles move very fast

A silver knife tarnishes is chemical or physical change

chemical

Elements

pure substance that contains only one type of material Ex: copper (Cu)

Compounds

contains two or more elements Ex: hydrogen peroxide (H2O2)

Mixtures

two or more substances that are physically mixed not chemically Ex: Na and Cl or Na + Cl

Homogeneous mixtures

the different parts of the mixture are not visible and are uniform throughout Ex: sugar water

Heterogeneous mixtures

the different parts of the mixture are visible Ex: pennies in water or spaghetti

What classification is air

Homogeneous

Is a hot fudge sundae hater or homo

Hetergenous

Solids

have a definite shape, definite volume, particles are close together, particles move very slowly

Liquids

have an indefinite shape but definite volume, particles are close together but mobile, particles move slowly

Gases

have an indefinite shape, an indefinite volume, the same shape and volume as their container, particles that are far apart, particles move very fast

A silver knife tarnishes is chemical or physical change

chemical

Length

uses unit of meter (m) in both metric and SI systems

Volume definition

the space occupied by a substance

Volume

Uses the unit Liter (L) in the metric system and uses the unit m³ (cubic meter) in the SI system

Mass definition

A measure of the quantity of material it contains

Mass

Uses the unit gram (g) in the metric system and uses the unit kilogram (kg) in the SI system

Temperature

Uses the celsius (^oc) scale in the metric system and uses the kelvin (k) scale in the SI system

Time

uses unit seconds (s) in both metric & SI systems

Scientific notation definition

used to write very small or large numbers

Measured numbers definition

Are the numbers obtained when you measure a quantity such as your height, weight, or temperature

Estimated number

The final number in your measured number

Significant figures

All non-zero numbers in a measured number are significant

Sandwich zeros

zeros between non-zero numbers are significant even with a decimal involved

Trailing zeros

trailing zeros without a decimal are not significant, with a decimal they are always are significant

Leading zeros

Precede non-zero numbers in a decimal number and are not significant

Significant figures in scientific notation

all digits including zeros in the coefficient are significant

How many significant figures are there in 0.030 m

2

Exact numbers

1. not measured and do not have a limited
   number of significant figures.

2. not used to find the number of significant
   figures in a calculated answer.

3. numbers obtained by counting.
   8 cookies

4. definitions that compare two units.
   1 kg = 1000 g

5. definitions in the same measuring system.

Calculations definitions

answers must have the same number of sig figs as the measured, calculator answers must often be rounded off, and rounding rules are used to obtain the correct number of sig figs

Multiplication and division

use the same number of sig figs as the measurement with the fewest sig figs when rounding

Multiplication rounding example: 110.5 × 0.048 =5.304

5.3

Division rounding example: 4.311/ 0.07=61.586

60

Both multiplication and division example: 2.54×0.0028/0.0105×0.060=11.2889

11

Addition and subtraction

use the same number of decimal places as the measurement with the fewest decimal places when rounding

addition rounding example: 235.05 + 19.6 + 2= 256.65

257

Subtraction rounding example: 58.925-18.2= 40.725

40.7

prefixes and equalities

1kg=1000g, 1g=100cg, 1g=1000mg

where are metals located on the periodic table

to the left of the line

Where are nonmetals located

to the right go the line

where are metalloids located

along the zigzag line

Metals

are shiny and ductile, and conduct heat and electricity

Nonmetals

are dull, brittle, have low densities/melting points, and are poor conductor but good insulators

Metalloids

better conductors then nonmetal but worse then metals. used as semiconductors and insulators, because they can be modified to function as conductors or insulators.

Protons

have a positive charge, are in the nucleus, has mass, does not move, and have a mass of 1

electrons

have a negative charge, are outside the nucleus, has space, moves, and have no mass

Neutrons

have no charge, is in the nucleus, has mass, does not move, and has a mass of 1

Atomic number

is the same number of protons in an atom

Number of electrons

the same as the protons

Mass number

equals the number of protons + the number of neutrons

Isotopes

atoms of the same element that have different mass numbers & different neutrons numbers but that same protons numbers

Atomic mass

the number on the periodic table below the chemical symbol

calculating atomic mass of a gallium sample:

60.10% of ⁶⁹Ga (atomic mass 68.926) atoms

39.90% of ⁷¹Ga (atomic mass 70.925) atoms

69.72

energy levels

n=1, n=2, n=3, and etc

levels to sub levels

the number of sub levels in a level is equal to the principal quantum number n of that energy level

Sublevels are identified how?

by s, p, d, and f

Example of levels to sublevel

n=4 equals 4 sublevels

Orbitals

Contains two electrons that must spins in the opposite direction and orbitals are always odd 1, 3, 5, 7

Maximum number of electrons that fill each sub level

• Each s sub level has 1 orbital and can hold a maximum of 2 electrons

• Each p sub levels has 3 orbitals and can hold a maximum of 6 electrons

• Each d sub level has 5 orbitals and can hold a maximum of 10 electrons

• Each f sub level has 7 orbitals and can hold a maximum of 14 electrons

How many electrons can occupy a p orbital

2

how many p orbitals are in the 2p sub level

3

how many d orbitals are in the n=4 energy level

5

how many electrons occupy the 4f sub level

14

what are the sub levels in level 3?

s,p,d

how many electrons are in level 3?

s-2 + p-6 + d-10 = 18

Valence electrons rules

• noble gas is never valence

• s&p are always valence

• d is valence if not 10

how many val e^-?

[Ne] 3s²3p³

2+3 =5

What are the val e^- for

[Ne] 3s²3p³

3s²3p³

how many orbitals and electrons are in the s sub level

1 orbital and 2 electrons

how many orbitals and electrons are in the p sub level

3 orbitals and 6 electrons

how many orbitals and electrons are in the d sub level

5 orbitals and 10 electrons

how many orbitals and electrons are in the f sub level

7 orbitals and 14 electrons

if n=4 what is the type of sub level?

4s, 4p, 4d, 4f sublevels

if n=3 what is the type of sub level?

3s, 3p, 3d sublevels

how many orbitals are there in 4f sub level

7 orbitals

how many orbitals in 4d sub level

5 orbitals

how many orbitals in 4p sub level

3 orbitals

how many orbitals in 4s sub level

1 orbital

how many orbitals in 3p sub level

3 orbital

how many orbitals in 3d sub level

5 orbitals

how many orbitals in 2s sublevel

1 orbitals

how to find how many electrons there are in energy levels

first figure how many sub level there are which would always be the same amount of levels. lets say it is 3 then we have to get s,p,d for our three sublevels. in s there are 2 electron in p there are 6 electrons, and in d there are 10 electrons then just add them all to together

how many electrons in n=4

32 electrons

d orbitals in the n=4 energy level is

5

If the thickness of the skin fold at the waist indicates an 11% body fat, how much fat is in a person with a mass of 86 kg?

9.5 kg fat