Chemical World

Question 1

Matter….(3 points)?

Answer 1

• occupies space
• has mass
• mainly composed of atoms

Question 2

3 physical states of matter?

Answer 2

• gas
• liquid
• solid

Question 3

Energy….(4 points)?

Answer 3

• does not take up space
• has no mass
• can be measured by its effect on matter ‘capacity to do work or put matter into motion’
• comes in a range of forms

Question 4

How can you transform matter from one state to another?

Answer 4

By adding or subtracting heat

Question 5

What are elements?

Answer 5

Substances made up of atoms which cannot be readily broken down into simpler substances eg. Oxygen, hydrogen, nitrogen, carbon

Question 6

What are molecules?

Answer 6

Two or more atoms joined together

Question 7

What is a chemical compound?

Answer 7

Is a molecule made of atoms from different elements eg. Water, carbon dioxide, sodium chloride

Question 8

How many elements in the periodic table?

Answer 8

92

Question 9

Atoms are made of?

Answer 9

• protons (+ve charge)
• neutrons (neutral, keep a nucleus stable when multiple protons)
• electrons (-ve charge)

Question 10

What is in the nucleus?

Answer 10

Protons and neutrons

Question 11

Where are the electrons?

Answer 11

Arranged in shells around the nucleus

Question 12

What is the atomic mass?

Answer 12

The number of protons in an atom

Question 13

What is the atomic weight?

Answer 13

Total number of protons and neutrons

Question 14

What is an isotope?

Answer 14

Variations in the number of neutrons held in the nucleus of an atom

Question 15

Isotopes can be…(3 points)?

Answer 15

• stable (effectively last forever)

- unstable Or radioactive (break down at varying rates)

Question 16

What is an ion?

Answer 16

An atom or compound that has gained or lost electrons to give it an overall positive or negative charge

Question 17

What is a cation?

Answer 17

An atom that loses an electron to become positively charged, fewer electrons than protons

Question 18

Icons readily…..?

Answer 18

Dissolve in water

Question 19

Key cations in the human body? (5 points)

Answer 19

• sodium ion Na+
• potassium ion K+
• calcium ion Ca2+
• magnesium ion Mg2+
• hydrogen ion H+

Question 20

What are anions?

Answer 20

Atoms of compounds that gain electrons to become negatively charged, fewer protons than electrons

Question 21

Key anions in the human body are? (3 points)

Answer 21

• chloride ion Cl-
• bicarbonate ion HCO3-
• phosphate ion PO43-

Question 22

What are ionic bonds?

Answer 22

Chemical bond formed between oppositely charged ions, electrons are completely transferred from one ion to another

Question 23

Ionic bonds happen between?

Answer 23

Metals and non metals so that all atoms have full charges

Question 24

Ionic compounds as solids? (3 points)

Answer 24

• form stable crystal lattices
• have high melting points
• tend to dissolve in water

Question 25

What are electrolytes?

Answer 25

Are positively and negatively charged ions found within the body’s cells and extra cellular fluids

Question 26

Common electrolytes in the body? (3 points)

Answer 26

- sodium - chloride - potassium

Question 27

What are covalent bonds?

Answer 27

Chemical bonds formed by atoms that share their electrons to form full outer shells

Question 28

What causes the bond?

Answer 28

Added electron density in the middle causes the two positive nuclei to draw together

Question 29

Covalent bonds are.....?

Answer 29

Strong, the more electron density in the middle the stronger the bond

Question 30

Single, double and triple covalent bonds are?

Answer 30

- 2 shared electrons - 4 shared electrons - 6 shared electrons

Question 31

What are covalent compounds?

Answer 31

- a molecule formed by covalent bonds | - generally results from 2 non metals reacting with each other

Question 32

Covalent compound characteristics? (3 points)

Answer 32

- lower melting points than ionic ocmpounds - include organic compounds in general ie. carbon, oxygen, hydrogen - include some very large molecules such as proteins

Question 33

What are hydrogen bonds?

Answer 33

- weaker type of bonding | - an attraction between the positive and negative poles of charged atoms

Question 34

What are the three classifications of chemical compounds?

Answer 34

- organic - inorganic - organometallic

Question 35

Characteristics of organic compounds? (7 points)

Answer 35

- contain both C and H - many atoms per molecule - often complex structures - made using (non-polar) covalent bonds - non-electrolytes - low melting points (<300) - combustible

Question 36

Characteristics of inorganic compounds? (6 points)

Answer 36

- may contain C or H, or neither, but never both - few atoms per molecule - ionic or polar covalent bonds - electrolytes (conduct electricity) - high melting point (>300) - non-combustible

Question 37

Examples of organic compounds? (4 points)

Answer 37

- glucose - protein - DNA - alcohol

Question 38

Examples of inorganic compounds? (3 points)

Answer 38

- water - carbon - salt

Question 39

What are functional groups?

Answer 39

A group of atoms whose bonding is the same from molecule to molecule, molecules with identical functional groups tend to have similar chemical and physical properties

Question 40

Hydroxyl functional group (-OH) occurs in?

Answer 40

- sugars | - alcohols

Question 41

Methyl functional group (-CH3) occurs in?

Answer 41

- fats and oils - steroids - amino acids

Question 42

Carboxyl functional group (-COOH) occurs in?

Answer 42

- amino acids - sugars - proteins

Question 43

Amino functional groups (-NH2) occurs in?

Answer 43

- amino acids | - proteins

Question 44

Phosphate functional group (-H2PO4) occurs in?

Answer 44

- nucleic acid | - ATP (adenosine triphosphate)