Chem 151

Elements within a group, which is shown as a ____, have similar _____.

Vertical Column, Chemical Problems

How many rows are in the periodic table? What are the rows called?

There are 7 rows. They’re called periods.

How many columns are there? The columns are called?

There are 18 columns, They’re called Groups.

Which experiment demonstrated the small size of the nucleus?

Rutherford's α-particle experiment.

Atomic Number (Z)

Number of protrons.protons.

Atomic Mass (A)

Protons plus neutrons/ #P+#N

Formula for Atomic Weight (f = Abudence/%) (m = Isotopic masses)

1. convert percentages to decimals (xx.xx%/100)

2. then plug into formula (f x m) + (f x m)

3. add both values

What is an ionic compound?

Positively charged ions (Metal) + negatively charged Ions (non-metals)

Dalton’s Atomic Model (1803)

An early atomic theory proposing that matter is made up of indivisible atoms, each with a unique mass and properties, and that atoms can combine in fixed ratios to form compounds.

Thomson’s atomic theroy (1897)

A theory by J.J. Thomson suggesting that atoms are composed of smaller particles, specifically electrons, embedded within a positively charged "plum pudding" structure.

Nitrate

NO_3^-

Nitrie

NO_2^-

Nitride

N_3^-

-Ate

Will always have one more oxygen then -Ite, with the exact charge

-Ite

An oxyanion containing one fewer oxygen atom than the -ate ion with the exact same charge.

-Ide

general rule is that it lacks oxygen