Lesson 2

Front 1

12 Elements commonly found in the body

Back 1

O-Oxygen C-Carbon H-Hydrogen N-Nitrogen P-Phosphorous Ca-Calcium K-Potassium S-Sulfur Na-Sodium Cl-Chlorine Mg-Magnesium Fe-Iron

Front 2

Matter

Back 2

All living & non-living things are composed of matter. Matter is defined as anything that has no mass but occupies space.

Front 3

Matter and chemical elements

Back 3

All matter is composed of chemical elements which cannot be broken down any further by ordinary chemical methods

Front 4

Mass

Back 4

Mass is a term used to describe the amount of matter in an object eg mass=weight

Front 5

Elements

Back 5

There are 112 different elements. 92 occur naturally on earth. 96% of your body is made up of O,C,N,H. Each element is represented by a symbol of 1 or 2 letters

Front 6

Atomic number & atomic mass

Back 6

An atomic number of an element is equal to the number of protons in the nucleus. Atomic mass is the number of protons plus the number of neutrons

Front 7

Cation and anion

Back 7

CATION-these are the ions which are positively charge. ANIONS-these are the ions which are negatively charged

Front 8

Atoms

Back 8

The smallest piece of an element, that has the same properties of that element. They are composed of subatomic particles. The 3 major ones are-protons, neutrons & electrons.

Front 9

Electron

Back 9

Electrons are negatively charged particles that are found moving around in space surrounding the nucleus of an atom

Front 10

Neutron

Back 10

Neutrons are particles that have no charge and are also found in the centre or nucleus of an atom

Front 11

Proton

Back 11

Protons are positively charged particles that are found in the centre of the nucleus of the atom. The number of protons ALWAYS equals the number of electrons

Front 12

Free radical

Back 12

An electrically charged atom or group of atoms that has in it’s outermost shell an unpaired electron

Front 13

Isotope

Back 13

Atoms of an element with different numbers of neutrons.They therefore have a different mass number

Front 14

Ion

Back 14

This is an atom that is positively or negatively charged because it has an uneven amount of protons to electrons due to losing or gaining an electron

Front 15

Molecule

Back 15

When two or more atoms share electrons, the combination which results is a molecule

Front 16

Inorganic compounds

Back 16

Inorganic compounds usually lack carbon atoms, are structurally simple, include water, many salts, acids and bases. They have either convalent or ionic bonds. HCO3 and CO2 are two who actually contain carbon

Front 17

Compound

Back 17

Is a substance that contains atoms that have two or more different elements

Front 18

Organic compounds

Back 18

ALWAYS contain carbon, & usually also contain hydrogen. They also ALWAYS contain convalent bonds. Eg fats, proteins, vitamins & carbohydrates

Front 19

Solution

Back 19

A solution is when one substance known as the SOLUTE is dissolved in another substance called a SOLVENT eg salt in water

Front 20

Acid

Back 20

An acid is a PROTON DONOR. Protons & hydrogen=same thing. When hydrogen atoms lose an electron they become a hydrogen ion(h+) or a single proton. So an acid is a substance that releases hydrogen ions when in a solution

Front 21

Salt

Back 21

A salt is a substance that dissociates into cations and anions, but DOESN’T release either hydrogen ions or hydroxide

Front 22

Ionic Bond

Back 22

Ions (cations/anions) with opposite charges are attracted to each other, like magnets. Therefore they stay close together. This attraction is a ionic bond. The bonds form cause opposites attract.

Front 23

Covalent bonds

Back 23

In covalent bonding atoms share electrons with other atoms in order to complete their electron shells, in doing this they share time around each atom, making them think their shell is full. They are stronger than ionic bonds

Front 24

Single covalent bond

Back 24

When 1 pair of electrons is shared

Front 25

Double covalent bond

Back 25

when 2 pairs of electrons are shared

Front 26

Triple covalent bond

Back 26

when 3 pairs of electrons are shared

Front 27

Polar covalent bond

Back 27

This is when a covalent bond is unequally shared, as in it spends more time around one atom then the other

Front 28

NON-polar covalent bond

Back 28

This is when the covalent bond is shared equally between the atoms

Front 29

Polar/Non-polar covalent bonds

Back 29

Electrons spend more time around one area than others & it creates a slight negative charge in one area & a slight positive in another. Molecules with this characteristic are known as polar molecules

Front 30

Hydrogen bonds

Back 30

This type of bonding doesn’t involve the sharing or exchange of electrons. Instead it’s a weak attraction between the slight negative & positive charges of polar molecules. Hydrogen bonds are weaker than ionic or covalent bonds

Front 31

Chemical reactions

Back 31

These are interactions between atoms, molecules or ions that lead to chemical bonds being broken or formed. Substances that enter into the reactions are REACTANTS, the results are PRODUCTS. Metabolism is the sum of all chemical reactions in the body.

Front 32

Decomposition reactions

Back 32

This is when larger molecules are broken down into smaller molecules, atoms or ions. Chemical bonds are broken. Known as CATABOLIC reactions

Front 33

Synthesis reactions

Back 33

Atoms, ions or molecules combine to form more complex & larger molecules. Chemical bonds are formed. Known as ANABOLIC reactions

Front 34

Exchange reactions

Back 34

This involves both the breaking and the forming of bonds, so are part decomposition and part synthesis. One part of a molecule is swapped to form two new molecules.

Front 35

Energy in chemical reactions

Back 35

In any chemical reaction some energy will be consumed & some produced. If more is released than consumed it is EXERGONIC, if more is consumed than released it’s ENDERGONIC

Front 36

Potential energy

Back 36

This is stored energy that has potential to perform work, but isn’t doing so

Front 37

Kinetic energy

Back 37

Kinetic energy is energy that causes an object to move or perform work

Front 38

Energy

Back 38

Is known in two forms -kinetic & potential energy. It can’t be created or destroyed but can change forms. It has no mass& doesn’t occupy space. It’s something that has the ability to move matter, do work or cause change

Front 39

Base

Back 39

A base is a substance that is a proton ACCEPTOR. Any substance that binds to hydrogen is a base.Many bases act as proton acceptors by releasing hydroxide ions(OH-) when they dissociate.

Front 40

Bases, acid & salts

Back 40

When an ionic molecule is dissolved in water the anions & cations separate in water & the water molecules surround the ion keeping them in the solution. How they separate determines whether they are acid, base or salt

Front 41

Body PH

Back 41

Your body controls the PH of all your body fluids. If it gets too acidic or basic the body returns PH to normal using buffer systems like the carbonic acid-bicarbonate buffer system

Front 42

PH scale

Back 42

A way of measuring acid/alkaline balance of the body based on the concentration of hydrogen ions. PH range goes from 1(acidic)-14(basic). The more hydrogen ion the more acidic. The more hydroxide the more basic (OH-).