Atoms
What is matter?
Any substance in the universe that has mass and occupies space.
What defines an element?
A substance made up of atoms with the same number of protons.
What are moleules?
What type of bond holds water molecules together?
Polar covalent bonds between partially negative O and partially positive H
Substances that dissociates in water to increase H+ conc.
Acids
Subatomic particles of an atom.
Protons, electrons, and neutrons
What are the 4 major elements of living things?
Oxygen, carbon, hydrogen and nitrogen
What are compounds?
Molecules containing more than one type of element.
What is the difference between cohesion and adhesion?
Cohesion: attraction of water molecules to each other due to their polarity.
Adhesion: water molecules sticking to other polar molecules by hydrogen bonding (meniscus).
How does a base change the pH?
Combines with H+ dissolved in the water and lowers the H+ conc., increasing pH.
What is atom mass?
Sum of protons and neutrons.
What are trace elements?
Small quantities of elements required for biological function such as catalysing reactions.
The three types of intramolecular chemical bonds?
Ionic, metallic and covalent
What is specific heat capacity and heat of vaporisation?
The energy required to change the temperature (of water) and the cooling of surfaces when evaporation occurs.
What is a strong acid/base?
Completely dissociates into it's ions, producing or absorbing H+.
Where are valance electrons?
Electrons in the outermost electron shell of an atom.
What is phosphorus required for?
Nucleic acid and phospholipid (membrane) synthesis.
What type of bonding does potassium and chloride form?
Ionic
What is a hydrophilic molecule?
Polar, 'water-loving'
What is a buffer?
A substance that resists changes in pH.
What is the difference between the isotopes C-12 and C-13?
C-12 has 6 neutrons. C-13 has 7 neutrons.
What are periods and groups?
The rows and columns of the periodic table.
What does the strength of covalent bonds rely on?
The number of shared electrons.
What is electronegativity?
The tendency for atoms to attract shared electrons within a chemical bond.
How does a buffer work?
Releases (base added) or absorbs (acid added) H+ such that [H+] is kept relatively constant.