Chapter 2: Elements, Compounds, and the Early Atomic Theory & Structure

An element is an e____ s____ that c____ be b____ d____ by any k____ c____ m____ into s____ s____.

elemental substance, cannot, broken down, known chemical means, simpler substances.

We have discovered ___ elements, of which ___ are known to occur in ____.

118, 88, nature.

The smallest particle of an elements that can exist is called an ____.

atom.

Metal elements are ____ at room temperature.
They have a h____ l____, are g____ c____ o____ h____ a____ e____, and are m____ as well as d____.

solid

high luster, good conductors of heat and electricity, malleable, ductile.

Metalloid elements are elements that have p____ that are i____ between those of m____ elements and those of ____-____ elements.

properties, intermediate, metal, non-metal

Non-metal elements have l____ m____ p____ and l____ d____.
They are n____ l____ and are p____ c____ of h____ a____ e____.

low melting points, low densities.
not lustrous, poor conductors, heat and electricity.

Diatomic molecules each contain e____ t____ a____.

exactly two atoms.

A compound is a d____ s____ that contains t____ o____ m____ e____ that are c____ c____ in a d____ p____ b____ m____.

distinct substance, two or more elements, chemically combined, definite proportion by mass.

A molecule is the s____ u____ i____ u____ of a c____ formed by the u____ of t____ o____ m____ a____.

smallest uncharged individual unit, compound, union, two or more atoms.

An ion is a p____ or n____ c____ a____ or g____ o____ a____.

positively, negatively charged atom, group of atoms.

A positive ion is also called a ____ while a negative ion is also called a ____.

cation, anion.

A c____ f____ shows the s____ and the r____ of the a____ of the elements in a c____.

chemical formula, symbols, ratio, atoms, compound.

____’s e____ model of the atom shows us that…:

1. e____ are composed of a____.

2. a____ of the same elements are a____ in terms of m____ and s____.

3. c____ are formed by the u____ of t____ o____ m____ a____ of d____ e____.

4. a____ form c____ in s____ n____ r____.

5. a____ of two elements may c____ in d____ r____ to form d____ c____.

Dalton’s, early

1. elements, atoms,

2. atoms, alike, mass, size.

3. compounds, union, two or more atoms, different elements.

4. atoms. compounds, simple numerical ratios.

5. atoms, combine, different ratios, different compounds.

The s____ parts of an atom consist of p____, n____, and e____.

subatomic, protons, neutrons, electrons.

State the mass (kg), charge, relative mass, and relative charge of a:

1. proton

2. neutron

3. electron

1. 1.672 × 10^-27, +1.602 × 10^-19, 1, +1

2. 1.675 × 10^-27, 0, 1, 0

3. 9.109 × 10^-31, -1.602 × 10^-19, 1/1836, -1

The a____ number of an elements is the number of p____ in the n____ of an atom of that element.

atomic, protons, nucleus

The m____ number of an element is the s____ of the number of p____ and n____ in the n____ of an atom of that element.

mass, sum, protons, neutrons, nucleus

An isotope is an atom of an element that has the s____ a____ n____ as that elements but has a d____ a____ m____ n____ of that element.

In other words, an isotope of an element has the s____ number of p____ but a d____ number of n____ in the n____ of that element.

same atomic number, different atomic mass number
same, protons, different, neutrons, nucleus