Ions form because most atoms are stable when they have this many valence electrons.
Eight
100
The number of these is the same before and after a reaction.
Atoms of an element
100
A kind of reaction that must be supplied with energy
Endothermic
100
What is the metric system unit of energy?
Joule
100
What are atoms with the same number of protons but different numbers of neutrons called?
Isotopes
200
This kind of molecule may form when the electronegativity difference is greater than 0.4 and less than 2.
Polar covalent
200
What is this number: 6.2x10^23
Avagadro's number = the number of atoms or molecules in a mole of substance
200
A kind of reaction that releases energy
Exothermic
200
What quantity is the same as a joule per second?
A Watt
200
This kind of radioactive emission is easy to stop.
Alpha particles
300
This kind of bond forms when the electronegativity difference is greater than 2 and forms materials with high strength, and high melting and boiling points, and high solubility in water.
Ionic
300
In the reaction 2H2 + O2 goes to 2H2O, how many moles of H2 are reacting with one mole of O2?
Two
300
The energy supplied to or released by a reaction
Enthalpy of reaction
300
What energy is formed when a mass is lifted vertically?
Gravitational potential energy
300
This kind of radiation can go through meters of material.
Gamma radiation
400
This kind of bond forms when the electronegativity difference is less than 0.4 and forms materials with less strength, low melting and boiling points, and low solubility in water.
Non-polar covalent
400
The molecular mass of oxygen gas is 32u. How many grams of oxygen gas are there in a mole of oxygen gas?
32 grams
400
The energy needed to form a reactant or a product
Enthalpy of formation
400
What is the equation for power (P) in terms of current (I) and Voltage (V)?
P = I x V
400
The time for half of the atoms of an unstable isotope to undergo radioactive decay.
The half-life
500
Why does salt easily dissolve in water?
Water is a polar molecule that attracts the sait ions.
500
If one mole of O2 reacts in the reaction 2H2 + O2 goes to 2H2O, how many grams of H2O are in the product? The molecular mass of H2O is 18u.
Two moles of H2O form, which has a mass = 2 x 18 = 36 grams.
500
What is the form of the energy created when hydrogen gas splits into hydrogen ions in a fuel cell?
Electrical energy
500
What types of energy are present in this energy system: a meteor enters the Earth’s atmosphere and burns up because of friction between the meteor and the air.
Kinetic energy is converted to internal energy that causes chemical energy to be released as radiation energy.
500
Name one major problem OR one major benefit of nuclear power.
Benefits: no greenhouse gasses emitted; efficient; low operating cost.
Problems: potential for accidents; storage of radioactive waste; expensive to operate; nuclear weapons; non-renewable; terrorism;