Elements
What is special about noble gases?
They are very stable
Ionic compounds are made from what types of elements in the periodic table
Metals and non metals
A chemical bond that shares electrons?
Covalent bond
What can you say is being formed if you see bubbles being made in a liquid?
A gas is being formed
Is HI Ionic or covalent?
Covalent because they are both nonmetals sharing electrons.
The number of protons in the nucleus in the nucleus of an element?
Atomic mass
What is an ion?
An atom or group of atoms with and electric charge
Define polar molecules.
A covalent molecule that has an uneven distribution of electrons, resulting in slight charges within the molecule itself.
When solid melts, what phase doe sit become? Was energy added or removed?
It becomes a liquid and energy is added
Is table salt (NaCl) an ionic or covalent and why?
Ionic because Sodium is a metal and Chlorine is a nonmetal. Their is a giving and taking away of electrons to make it more stable.
An atom gains 4 electrons to become stable like a noble gas. What charge does it have?
4 negative charges
Substances that are composed of positive and negative ions?
Ionic compounds
Define Nonpolar molecules.
A covalent molecule that has an even distribution of electrons so there is no net charges.
What change occurs in evaporation? Is energy added or removed from the substance to make it happen?
Liquid to gas. You add energy for this to happen.
Explain why wax or sugar has a low melting point?
It has nonpolar covalent bonds. It doesn't take much energy to break the attraction of molecules apart.
Define what an ion is?
An atom that becomes electrically charged because it has an imbalance of electrons and protons.
Which compounds are ionic?
KBr, SO2, Li2CrO4, NaNO3, C2H4O2
KBr, LI2CrO4, NaNO3 are ionic
Define the law of Mass Conservation
In any non-nuclear process, the total mass of everything involved must remain the same.
Mass is neither created nor destroyed in chemical reactions.
The mass of any element at the beginning of a reaction will equal the mass of that element at the end of the reaction no matter how it rearranges in space.
Consider a lake. There are water molecules in the lake, and they are in the liquid phase.
There are oxygen molecules in the air above the lake, and they are in the gas phase.
There is Calcium Carbonate in the solid rocks at the bottom of the lake.
Order the the molecules in terms of how fast they are moving.
Calcium carbonate, then water, and then the oxygen.
Molecules in solids only vibrate a little. Liquid molecules move around more, but not quickly.
Gases move around very quickly.
What are the outermost electrons of an atom called?
Valence electrons
Which would producing higher-energy light? Berilium (Be) or Oxygen (O)
Oxygen would produce light of a higher energy because it has a higher atomic number. The higher atomic number, the higher the charge of its nucleus. THe higher the charge, the more energy that is in the light it emits.
What is the chemical formula and name of the compund formed when Aluminum (Al) and Bromine (Br) are mixed together?
Its aluminum bromide, AlBr3
Al is a metal, so it loses ans electron to become more like th nearest noble gas. That means it loses an 3 electrons to become like Ne. So it becomes Al+3.
Bromine is a nonmetal, so it gains electrons. It gains one electron to become like Kr, so it is Br-. The charges must cancel, so it will take three Br- to cancel the charge on one Al+3.
We name the compound by using the name of the element that becomes a positive ion and put "ide" ending on the element that becomes the negative ion.
You have a liquid that is composed of polar molecules and one that is nonpolar molecules.
a. Which liquid is made of molecules that have slight charges in them?
b. Which had the weaker attraction between molecules?
c. Will the two mix well together?
a. Polar liquid
b. Nonpolar
c. They will not mix well together
You have two samples of water, one is in its liquid phase, and the other is in its solid phase. They both take up exactly the same volume. Are their masses different or the same? If different, which has more mass?
The water in its liquid phase has more mass.
Water expands when it freezes. The same mass of ice, then, would take up more volume. SInce both take up the same volume, the ice must have less mass.
Diagram the Lewis Structure of table salt.
See white board diagram