Honors Chemistry Unit 2: Matter and Chemical Bonding

What is matter?

Anything that occupies space and has mass

What is an atom?

Submicroscopic particles athat are the fundamental building blocks of matter

What is a molecule?

Two or more atoms joined in a specific arrangement by chemical bonds

What are the states of matter?

Solid, liquid, gas

What is a pure substance?

A substance composed of only one type of atom or molecule

What is a mixture?

A substance composed of two ore more different types of atoms or molecules combined in variable proportions

What is an element?

A substance that cannot be broken down into its simpler substances

What is a compound?

A substance composed of two or more elements in fixed, definite proportions

What is a heterogenous mixture?

A mixture (such as oil and water) with composition that varies from one region to another

What is a homogenous mixture/solution?

A mixture (such as salt and water) that has the same composition throughout

What are physical properties?

A property that a substance displays without changing its composition

What are chemical properties?

A property that a substance cna display only through changing its composition

What is physical change?

A change in which matter changes its appearance, but not its composition.

What is a chemical change?

A change in which matter changes its composition

What is a chemical reaction?

A process where one or more substances transforms into different substances via a chemical change, often emit or absorb energy

What are reactants?

An initial substance in a chemical reaction, represented on the left side of a chemical equation

What are products?

A final substance produced in a chemical reaction, represented on the right of a chemical equation

What is decanting?

A way to separate a mixture in which one layer is carefully poured off of another layer

What is disillation?

A way to separate mixtures in which the mixture is heated to boil off the more volatile component

What is filtartion?

A way to separate a mixture of a solid and liquid using a barrier that liquid can pass thourugh but the solid cannot

What does the Law of Conservation of Mass say?

“Matter is neither created nor destroyed in a chemical reaction”

What is a chemical bond?

A force that holds groups of 2 or more atoms together to function as a unit

What is a ionic bond?

An atom (metal) transfer an electrostatic attraction of a positively charged in and a negatively charged ion

What cation?

An ion with positive charge

What anion?

An ion with negative charge

What is the formula unit?

The lowest whole # of ratio of the ions in an ionic compound

What are the properties of ionic compounds?

Most are crystalline solids at room temperature, generally have high melting points and can conduct an electric current when melted or dissolved in water.

What is a covalent bond?

Bonding where electrons are shared by 2 nuclei

What is a molecular compound?

A compound composed of nonmetals covalently bonded together as individual molecules

What are properties of molecular compounds?

They tend to have relatively lower melting and boiling points than ionic compounds

What is a single covalent bond?

One pair of e- shared between 2 atoms

What is a double covalent bond?

Two pairs of e- shared between 2 atoms

What is a triple covalent bond?

Three pairs of e- shared between 2 atoms

What is a nonpolar covalent bond?

A covlanet bond with equal sharing of electrons between the nuclei

What is a polar covalent bond?

A covalent bond with unequal sharing of electrons between the nuclei. The higher the atom’s electronegativity, the closer the shared electrons tend to be to that atom when it forms a bond.

What does the polarity of a bond depend on?

The difference in eelctronegativity between the 2 bonded atoms

When will a covalent bond typically occur?

Where an atom has a ½ filled orbital

What is electron promotion?

One e- from a full s orbital moves to an empty p orbital in the same quantum level.

What is the Lewis structure?

A representation of a molecule that shows how the valence e- are arranged among the atoms in the molecule

What does the octet rule state?

8 electrons are required to fill in the s and the p orbitals in the valence energy level (exception: duet rule- 2 electrons for hydrogen)

What are bonding pairs?

e- that are shared between 2 atoms

What are lone pairs?

e- that are not involved in bonding

What is a terminal atom?

an atom that has only one bondind site (this i sfound on the end of molecule)

What is the structural formula?

The overall shape of the molecule is represented by element symbols and a single covalent bond is represented by a straight line or dash

What are isomers?

Substances that have the same chemical formula but different strcutres

What does the valence shell electron pair repulsion (VSEPR) theory state?

That the repulsion between electron pairs/regions causes molecular shapes to adjust so that the valence electron pairs/regions stay as far apart as possible.

Wen using the VSEPR model to predict the molecular geometry of a molecule, what is a double bond or triple bonded counted as?

One region of electrons

How do you tell when a molecule is polar?

When the dipole movements of the bonds do not cancel.

What is molecular structure?

The shape of the moelcuel focusing on the atoms bonded to the center atom?

What is electron strcutre?

The shape of the molecule focusing on the lone electrons and the bonded toms around center atom

What does the electronic structure and molecule structure look like for a 2 electron pairs with 2 bonds?

Electron Pair Arrangement: Linear

Molecular Structure: Linear

What does the electronic structure and molecule structure look like for a 3 electron pairs with 3 bonds?

Electron Pair Arrangement: Trigonal Planar

Molecular Structure: Trigonal Planar

What does the electronic structure and molecule structure look like for a 4 electron pairs with 4 bonds?

Electron Pair Arrangement: Tetrahedral

Molecular Structure: Tetrahedral

What does the electronic structure and molecule structure look like for a 4 electron pairs with 3 bonds?

Electron Pair Arrangement: Tetrahedral

Molecular Structure: Trigonal pyramid

What does the electronic structure and molecule structure look like for a 4 electron pairs with 2 bonds?

Electron Pair Arrangement: Tetrahedral

Molecular Structure: Bent or V-shaped