Matter organisation and chemical reactions Flashcards
Describe the structures of atoms, ions, molecules, compounds and free radicals
What is the distinction between an atom and an element?
Elements are made up of their atoms, which will all have the same number of protons in their nucleus
E.g. carbon is made up of atoms which have 6 protons in their nucleus
The amount of which subatomic particle in an atom is consistent between different ions and isotopes?
The number of protons
This dictates an atom/element’s atomic number
The amount of which two subatomic particles is the same in an atom?
The protons and electrons, therefore atoms are electrically neutral
What is an ion?
An atom which has lost or gained one or more of it’s electrons and therefore has a positive or negative charge
The amount of which subatomic particle differs between isotopes?
Neutrons
The sum of which two subatomic particles equals an atoms mass number?
Protons and neutrons
How many electrons can be held in the following electron shells?
1. First shell
2. Second shell
3. Third shell
- 2
- 8
- 18
What is a molecule?
Two or more atoms sharing electrons
What is a compound?
A substance containing two or more different atoms
All compounds are molecules but not all molecules are compounds e.g. O₂
What is a free radical?
An atom or molecule with an unpaired electron/odd number of electrons in it’s outermost (valence) shell
How does a radical differ from an ion?
- All ions are charged whereas radicals can be neutral or charged
- Radicals are unstable and highly reactive
Why are radicals harmful to the body?
They are highly reactive and therefore will break apart important body molecules to lose or gain an electron to become stable
Name some sources of free radicals
- UV radiation in sunlight
- X-rays
- Ozone
- Cigarette smoke
- Air pollutants
Name some conditions linked to free radicals
- Cancer
- Atherosclerosis
- Alzheimer’s disease
- Emphysema
- Diabetes
- Cataracts
- Macular degeneration
- Rheumatoid arthritis
Name some dietary antioxidants
- Selenium
- Zinc
- Beta-carotene
- Vitamin C
- Vitamin E
What types of foods are typically high in antioxidants?
Red, blue or purple fruits and vegetables
List the four key features of organic compounds
- Always contain carbon
- Usually contain hydrogen
- Always have covalent bonds
- Most are large molecules
List the three key features of inorganic compounds
- Usually lack carbon (exceptions include CO₂, HCO₃ and H₂CO₃)
- Are structurally simple, their molecules have only a few atoms e.g. water, salts, acids and bases.
- They can have ionic or covalent bonds.
What type of reactions in the body does anabolism refer to?
Synthesis reactions - when atoms, ions or molecules combine to form new and larger molecules
Are anabolic reactions usually exergonic or endergonic?
Endergonic - they absorb more energy than they release
What type of reactions in the body does catabolism refer to?
Decomposition reactions - the splitting up of larger molecules in to smaller molecules, ions or atoms
Are catabolic reactions usually exergonic or endergonic?
Exergonic - they release more energy than they absorb
Besides synthesis and decomposition reactions, what are the other three types of reaction in the body?
- Exchange - a combination of synthesis and decomposition (ions are exchanged)
- Reversible - can occur in either direction under the right conditions
- Oxidation-reduction - used to break down food molecules to produce energy
What are monomers and polymers?
Monomers are molecules that can be bonded to other identical molecules to form a polymer
