Nurse Shai Hesi Chem

Chemistry

The study of the properties of matter and the changes it undergoes

Matter

anything that takes up space and has a mass

Mass

Measure of matter that an object contains

Substanace

matter that has a definite or constant composition and distinct properties

(compounds and elements)

Mixture

a combination of two or more substances in which the substances retain their distinct identities

(homogeneous and heterogeneous)

Compound

a substance composed of two or more elements

Element

a substance that cannot be separated into simpler substances by chemical means

(one type of atom + cannot be chemically broken down.)

An atom is composed of 3 different components

Protons, neutrons, and electrons

Electrons have what type of charge and where are they located?

Negative charge and located on the outermost shell of the atom

Where are the protons and neutrons located?

inside the atom’s nucleus

What charge are the protons?

positively charged

What charge are the neutrons?

No charge

Homogenous Mixture

A uniform mixture (when stirred the mixture looks the same)

Ex: Stirring matcha and water

Heterogenous Mixture

Not a uniform mixture ( you can see the different substances)

Ex: Pizza

Solvent

dissolves the solute (does the dissolving)

Ex: water

Solute

add to the solvent (gets dissolved)

Ex: salt

Solution

Homogeneous mixture consisting of a solvent and solute

Ex: Salt water

The periodic table is arranged in

groups and periods

Group number shows how many what?

electrons are in a shell

Groups are arranged

vertically (up and down)

Periods are arranged

horizontally (left to right)

Heavy metals are at the

bottom

Lighter metals are located at the

top

Atomic number

The number at the top of the element tells you the number of protons in that element

Atomic mass

number of protons and neutrons (at the bottom of each element)

Identify how many protons and neutrons in Sodium?

Protons = 11

Atomic mass = 22

Neutrons = 11 (22-11)

Identify how many protons and neutrons in Nitrogen?

Protons = 7

Atomic mass = 14

Neutrons = 7 (14-7)

Identify how many protons and neutrons in Aluminum?

Protons = 13

Atomic mass = 26

Neutrons = 13 (26-13)

Identify how many protons and neutrons in Magnesium?

Protons = 12

Atomic mass = 24

Neutrons = 12 (24-12)

Most metals are on which side of the periodic table?

Left side

Most nonmetals are on which side of the periodic table?

Right side, except for Hydrogen (top left)

(H, C, N, O, F, P, S, Cl, Se, Br, I, and the noble gases.)

Where are the metalloids on the periodic table?

On the staircase

(B, Si, Ge, As, Sb, Te -metals & nonmetals)

Group 1 (+1 charge)

Akali metals

Group 2 (+2 charge)

Alkaline earth metals

Group 17 (-1 charge)

Halogens

Group 18 (no charge)

Noble Gases

full outer shell = don't want to react

• Helium (He)

• Neon (Ne)

• Argon (Ar)

• Krypton (Kr)

• Xenon (Xe)

• Radon (Rn)

• Oganesson (Og)

Molecular mass (molecular weight)

sum of the atomic masses in a molecule

What is the molecular weight of C2H5OH (Ethanol)?

C = 12 (molar mass) x 2 (number of carbons) = 24

H = 1 (molar mass) x 6 (number of hydrogens) = 6

O = 16 (molar mass) x 1 (number of oxygens) =16

24 + 6 + 16 = 46 g/mol

What is the molecular weight of SO2 (Sulfur Dioxide)?

S = 32 g/mol x 1 = 32

0 = 16 g/mol x 2 = 32

32 + 32 = 64 g/mol

Scientific Notation

The scientific system of writing very big or very small numbers easily

3.2 to scientific notation

3.2 × 10⁰

4.28 × 10⁻⁵ to scientific notation

0.0000428

602,000,000 standard to scientific

6.02 × 10⁸ (bigger numbers have a positive exponent)

For science notation when the exponent is positive you move the decimal to the

right (bigger numbers have a positive exponent)

For science notation when the exponent is negataive you move the decimal to the

left

KHDBDCM

Kilo → Hecto → Deka → Base → Deci → Centi → Milli

(King Henry Died By Drinking Chocolate Milk 🥛🍫)

Kilo

1000

Hecto

100

Deka

10

Base

1

Deci

0.1

Centi

0.01

Milli

0.001

Ions

When an atom is electrically charged and is in an ionic state, it loses electrons (cation) or gains electrons ( anion)

Cation

positive charged- gains protons and loses electrons

Anion

negative charged -loses protons, gains electrons

Isotopes

Atoms of the same element but with different mass numbers (therefore different neutrons)

3 states of matter

liquid (l), solid (s), gas (g)

Liquid’s volume, shape, movement, and particle spacing

Volume: definite

Shape: takes the shape of its container

Density: medium high (slightly compressible)

Movement: slides past each other

Particle spacing: Close (not as close as solids)

Solid’s volume, shape, movement, and particle spacing

Volume: definite

Shape: definite

Density: highest ( not compressible)

Movement: vibrate

Particle spacing: Tightly packed together

Gas volume, shape, movement, and particle spacing

no fixed shape + no fixed volume + low density + highly compressible + particles far apart + particles move freely.

Freezing point in Celsius

0°C

Freezing water in Fahrenheit

32°F

Normal body temp in Celsius

37°C

Normal body temp in Fahrenheit

98.6°F

Boiling water in Celsius

100°C

Boiling water in Fahrenhiet

212°F

F to C formula

°C = (°F − 32) × 5/9

C to F formula

°F = (°C × 9/5) + 32

C to K formula

K = °C + 273.15

Convert 68 F to C

=(68 − 32) × 5/9
= 36 × 5/9
= 20°C

Convert 40 C to F

= (40 × 9/5) + 32
= 72 + 32
= 104°F ✅

Convert 23 C to K

23 + 273.15 = 296.15 K

Chemical Change

when an original substance is transferred into a new substance with different properties

Physical Change

Transformations that do not produce new substances

Covalent Bond

formed when two atoms share electrons, generally in pairs. The strongest of any type of bond.

Ionic Bond

an electrostatic attraction between two oppositely charged ions, a cation, or an anion. Generally formed between a nonmetal and a metal (Na+Cl-)

(transfer electrons + opposite charges attract.)

Alpha Radiation

The largest of the radioactive waves. Can be stopped by a sheet of paper.

Beta Radiaiton

−1 charge → stopped by aluminum

a fast-moving electron that is released from an unstable atomic nucleus.

Gamma Raditation

Similar to X-rays. Can penetrate through concrete and lead

pH scale measures

how acidic or basic a solution is by the concentration of hydrogen ions (H⁺)

• More H⁺ → lower pH → more acidic

• Less H⁺ → higher pH → more basic

Acidic on the scale

0–6 (battery acid, stomach contents, lemon juice, wine)

• More H⁺ (donates hydrogens)

Neutral on the scale

7 (pure water)

Basic (alkaline) on the scale

8-14 (intestinal contents, soap, household ammonia, bleach)

• Less H⁺ (loses hydrogen)

PH of blood

7.35–7.45

Synthesis

Two elements combine to form a product

A + B —> AB

C + O —> CO

Decomposition

breaking down of a compound into component parts. Opposite of Synthesis

AB —> A +B

Combustion

A chemical reaction where oxygen and fuel react ( burning of the gases). Will always contain CO2 + H2O as a product

CH4 + O2 —> CO2 + H2O

C3H8 + O2 —> CO H2O

2CH6 + 7O2 —> 4CO2 + 6H2O

Single Replacement

Reactions consist of more than one active metal reacting with ionic compounds. Once an element starts out by itself and ends up kicking another element out

Cu + 2 Ag NO —> Cu (NO3)2 + 2Ag

Double Replacement

Reactions that involve two ionic compounds. The positive and negative ions compounds switch places (everyone has a dancing partner)

Ag NO3 + KCl —> AgCl + KNO3

Intermolecular Forces

attractive forces between molecules. (hydrogen, dipole-dipole, and dispersion)

Hydrogen Bond

Attraction for a hydrogen atom by a high electronegative element. Usually involving F, O, N.

H2O, NH3, CHCL3

H–N, H–O, or H–F

*strongest bond of them all

Dipole Dipole

The attraction of a dipole on one molecule for the dipole of another molecule. When an electron is shared unequally.

An intermolecular force that happens between polar molecules. (The positive end of one molecule attracts the negative end of another molecule)

NA+Cl-

H+Cl-

opposites

Dispersion

When electrons temporarily concentrate on one side of an atom or molecule, they create a temporary (momentary) dipole.

CH4, SO2

*weakest

Carbohydrates

The main function is to provide energy.

Deoxyribose, Ribose, Glucose (C6H12O6) Saccharide, Glycogen, and Pentose

Proteins

• 20 amino acids → The body uses 20 standard amino acids to build proteins.

• Peptide → A short chain of amino acids.

• Polypeptide → A long chain of amino acids.

• Protein → One or more chains of amino acids folded into a specific shape.

• Albumin → A protein made of 585 amino acids.

Lipids

Main functions: insulation, body temperature, cell function, energy storage

Fat, oils, cholesterol, and fatty acids

Fatty acids are made up of COOH (carboxyl functional group)

Glycerides - triglycerides - 3 fatty acids

Nucleic Acids

includes DNA and RNA - contains genetic information

O.I.L R.I.G

Oxidation Is Loss of electrons

Reduction Is Gain of electrons

Oxidation/reduction (redox)

reactions where electrons are transferred