Ch 02 Chemical Properties Flashcards
What is an atom?
The smallest unit of matter that cannot be divided. Also smallest particle which retains properties of an element. Composed of electrons, protons, and neutrons.
What is atomic number?
The number of protons in the nucleus
What is atomic weight?
The number of protons and neutrons
What is an isotope?
The atom has a different number of neutrons. C12, C13, C14
What are the biological elements?
95% carbon, oxygen, nitrogen and hydrogen
What is the molecular weight of a molecule?
The sum of the atomic weight of all the atoms
What is radioactivity?
Unstable number of protons and neutrons
What is ionic bonding?
An atom that gains or loses electrons
What is covalent bonding?
Electron sharing H:C
What is hydrogen bonding?
H polar (unequal) bonding to N, O, F
Which type of chemical reaction releases energy?
Exothermic
What is one mole?
The molecular weight in grams
Ex. water 2H=2x1=2 1O=16 the molecular weight of water is 18
What is condensation?
Water removal AKA dehydration
What is hydrolysis?
Breaking molecular bonds using water
What are the three laws of thermodynamics?
- E cannot be created or destroyed.
- Entropy - no energy transformation is 100%
- Conservation of matter
Are exothermic or endothermic are more likely to occur?
Exothermic because they are more chaotic
What element is needed for an organic molecule?
Carbon!
Is water organic or inorganic?
Inorganic!
What are four characteristics of water?
- Polar molecule
- A good solvent
- Temperature buffering
- Surface tension
What is the formula for pH?
pH = -log10 [H-]