Flashcards in Week 2 Deck (57)
How much it weighs, units are called "U". The protons and neutrons together determine the atomic weight of the atom. The electrons' mass is so tiny, it doesn't contribute to the atomic weight.
Every eight elements, there are repeated chemical groups
Periodic table is split into two groups
1. Representative group = their electrons represent (shown by "A" in my table)
2. Transition Group = their electrons drop an energy level. Bottom two rows drop two energy levels (shown by "B" in my table)
Noble gases are the "cool people in HS":
1. Every element wants to act like a noble gas
2. They are very stable, hard to change.
3. They have a full electron shell (=satisfied), makes them super-stable.
4. Also known as inert gases.
5. They complete the octave rule.
1. Have one electron in their outer shell.
2. They are readily reactive with water.
Every period represents ...
... an energy level.
Alkaline Metals are ...
...also pretty active with water.
Halogens really want to ...
Actinide series are ...
...man-made, radio-active. They have few good things, e.g. smoke detectors, can detect a neuron reaction.
The outer shell electrons, the ones that matter.
What's its valencity?
What does it do more likely (give up or gain an electron)?
Metals are ...
...good conductors of two things, heat and electricity.
They are shiny.
They only one that is liquid at room temperature is Mercury.
...come in two forms, solids & gases. The only non-metal that is liquid at room temperature is Bromine.
A compound is ...
... two elements combined at a specific ratio.
A molecule is ...
...the smallest unit of a compound that retains the properties of that compound.
In carbon dioxide you have ...
... a double bond.
Measuring percentage in chemistry
- for accuracy, increases our chance for success
- we know the amount of substance matters
- a lot of times we measure concentration in %
Basic % equation:
X : X Total x 100 = %
Oxygen influences ...
...our life most.
It is a useful physical property to enable chemists to more easily identify substances.
Density = Mass (g) : Volume (ml)
Water's density is 1.
1 ml of water equals 1 g.
Densities of liquid ...
... will vary based on temperature.
We need to make sure to measure liquids at 68 F.
Kinetic energy is energy of movement. On a chemical level, it's the energy of movement of the particles.
Potential energy w/in chemistry is ...
... stored energy (stored in chemical bonds). Example: ATP has explosive, potential energy.
Heat is being given off by the bond breaking off.
(e.g. Kitchen match, exothermic reaction, cannot relight once burnt off = low energy at end)
Energy being pulled into (e.g. Sunlight, Water, Seed turns into tree at the end)
Energy is ...
...in the bonds. Fat has lots of energy.
9 calories in 1 g of fat
4 calories in 1 g of carbohydrates or protein