Chem Exam 2

Core electrons

remain close to the nucleus and usually don't participate

Valence electrons

The outermost electrons that interact with other atoms and where bonding occurs

Atoms

consists of protons neutrons and electrons

ex: Mg

Molecules

two or more atoms chemically bond together

ex: MgCl2

Ions

an atom or molecule that has gained or lost electrons, giving it a positive or negative electrical charge

ex: Mg^2+

Pure substance

-Made of only 1 type of particle (element or compound)

-fixed composition

Mixtures

-combine pure substances physically and can be separated

-can be homogeneous (same throughout) or heterogeneous (different parts visible)

Physical change

Alters a materials form/appearance without changing its chemical composition

Chemical change

creates a new substance with different molecular composition

Ionic bonds

usually form between metals and nonmetals. Metals lose electrons and become positively charged, while nonmetals gain electrons and become negatively charged. These opposite charges hold the atoms together

Covalent bonds

Form when 2 nonmetal atoms share electrons. This sharing allows both atoms to complete their outer shells, making the molecule stable. Covalent bonds are represented as a line, each line showing 2 shared electrons. There is no transfer, just sharing for stability

Conservation of mass

The law states matter cannot be created nor destroyed in a chemical reaction. The total mass before and after a reaction is the same

The mass of reactants= mass of product

NH+4

Ammonium

CO3 ^2-

Carbonate

OH-

Hydroxide

NO3 ^1-

Nitrate

SO4 ^2-

Sulfate

PO4 ^3-

Phosphate

covalent, ionic, or both?: KI

ionic

covalent, ionic, or both?: H2O2

covalent

covalent, ionic, or both?: Li2CO3

both

ionic or covalent?: NCI3

covalent

ionic or covalent?: MgCl2

ionic

ionic or covalent?: CCI4

covalent

ionic or covalent?: NF3

covalent

What is the symbol for BaO?

Ba^2+O^2-

What is the symbol for Na2O?

(Na^1+)2 O^2-

Does NaCN have covalent bonds?

yes

Does P4O10 have covalent bonds?

yes

Does Rb2S have covalent bonds?

no

draw the structure for: HBr

Draw the structure for: CICH2Br

Draw lewis structure for: NH3

Draw lewis structure for: CH3NH2

Draw lewis structure in order written: CH3OCH3

Draw lewis structure with 3 bonds between C and C: CHCH

What is the chemical formula for: Zinc(III)phosphate

Zn3(PO4)2

What is the chemical formula for: Ammonium nitrate

NH4NO3

What is the chemical formula for: Sodium hydrogen sulfate

NaHSO4

what is the name for: V2O5

Vanadium (V) oxide

what is the name for: NH4NO3

ammonium nitrate

what is the name for: Hg(OH)2

Mercury (II) hydroxide

what is the name for: KNO3

potassium nitrate

VSEPR

Valence shell electron pair repulsion

Make as far as possible

Molecular geometry for: BeCl2

linear

Molecular geometry for: BH3

Trigonal planar

Molecular geometry for: H2O

Bent

Molecular geometry for: CH4

Tetrahedral

Molecular geometry for: NH3

Trigonal pyramidal

Trigonal pyramidal

1 lone pair, tetrahedral, 4 electron dense areas

Linear

0 lone pairs, linear, 2 electron dense areas

Bent

1 lone pair, trigonal planar, 3 electron dense areas or

2 lone pairs, tetrahedral, 4 electron dense areas

Tetrahedral

0 lone pairs, tetrahedral, 4 electron dense areas