Atomic Theory (On Learning Objectives)

Elements ___ break down further. There are only 7 elements that are found as diatomic molecules. Name them. (Have No Fear Of Ice Cold Beer)

cannot; H2, N2, O2, F2, Cl2, Br2, I2

Atoms are the ____ unit of matter. Compounds are composed of two or more ___ elements.

smallest; different

Who proposed the atomic theory?

John Dalton

What are the four things the atomic theory states?

1. Matter is composed of ___

2. Atoms of the same element are ___ and have the ___ mass.

3. Chemical compounds form in ___ number ratios

4. Atoms in a chemical reaction are ___, they are not ___ nor ___

1. Matter is composed of atoms

2. Atoms of the same element are identical and have the same mass

3. Chemical compounds form in whole number ratios

4. Atoms are rearranged in a chemical reaction, they are not created nor destroyed

Who discovered the electron using cathode rays and discovered that they are tiny, negative, and was smaller in mass compared to protons?

JJ Thomson

Who discovered the electron’s charge and a more precise measurement of the electron’s charge? Hint: Oil-drop

Millikan

What is the absolute charge of the electron?

1.602177 × 10^-19 C (coulomb)

Who discovered the nucleus in 1911 and proved that atoms are mostly empty space with a dense, positively charged nucleus? What experiment did he use?

Rutherfold used the gold-fold experiment

What is 1 amu in kg?

1 amu = 1.661 × 10^-27 kg

What is the mass of a proton, neutron, and electron?

Proton: approx 1.007 amu
Neutron: approx 1.009 amu
Electron: approx 5.5 × 10^-4 amu

Protons control the element’s ___, whereas electrons control the ___

identity; charge

Location and charge of p+, n, and e-?

p+ = nucleus charge +1
n = nucleus, charge 0
e- = electron cloud, charge -1

In this photo, the mass number is ____, the number of protons is ___, and the charge is ___

127, 53, -1

How do you find the number of neutrons?

Mass number - Atomic number

How many electrons are in O²-? How about in Mg²+?

O = 8 protons, 10 electrons

Mg = 12 protons, 10 electrons

What is an isotope

They are the same number of protons but with differing numbers of neutrons.

True or False: The atomic mass on the periodic table is considering all known isotopes combined?

True

Cations are ___ charged overall, meaning they ___ electrons. Usually they are ____

Anions are ___ charged overall, meaning they ___ electrons. Usually are ___

positively; lose; metals

negatively; gain; nonmetals

Monoatomic cations are named by adding the word ___ at the end. For instance, Na+ would be called a ___ ___

ion; sodium ion

With some cations, specifically in the transition metals, we use Roman Numerals to specify the charge. The “no-numeral” list consists of 2 groups and 5 elements. What are they? (Use table if needed)

Group 1 and 2, Ag+, Zn2+, Cd2+, Sc3+ Al3+

With monoatomic anions, you add ___ at the end of the element + ____ For instance: Cl- would be a ____ ____

-ide; ion; chloride ion

In compounds, the ___ element takes the name. For instance, NaCl is called ____ ___

sodium chloride

Oxoanions are ____ anions that have one or more ___ atoms and one atom of another element.

polyatomic; oxygen

The most common form of oxoanions in a series change the central element’s name to ___ and adding the word ___. For instance, ClO3^- is the most common form, and it’s called ___ ___

-ate; ion; chlorate ion

Two less oxygens that the most common ionic form has ___ in front, ___ at the end, and the add the word ___. For instance; ClO- is called ____ ____

hypo; ite; ion; hypochlorite ion

One less oxygen than the most common ionic form has ___ at the end and add the word ___. For instance, ClO2^- is called a ____ ____

ite; ion; chlorite ion

One more oxygen than the most common ionic form has ___ in the beginning, ___ at the end, and adds the word ___. For instance, ClO4^- is called a ____ ____

per; ate; ion; perchlorate ion

Mass number is equal to ___ + ___ for an isotope, whereas atomic mass is the ___ ___ on the periodic table.

protons, neutrons, weighted average