Atoms, Elements, and Compounds

hypoatremia

low blood sodium, that is consistent with water intoxication

atoms

are the basic building blocked of a human being, as well as everything else in the universe, living and nonliving

matter

all things that have mass are _____

chemistry

the foundation of understanding of health and nutrition, fuels and energy, the raw materials of our world and the things we can make from them, and the nature of our bodies

intensive properties

do not depend on the size of the sample selected
- examples: color and density

extensive properties

depend on the size of the sample chosen
- examples: mass and volume

mixture

can have different proportions of its ingredients
- example: salt water
- tend to look and act like their components (looks like water and tastes like salt)

chemical substance

a __________ only has one possible composition
- example: table salt, NaCl (always 50% and 50% Cl)

compounds

are different from their components

salt water

a mixture, because it contain different proportions water and salt

compound

salt is a __________, because all samples of salt have the same proportions of sodium and chlorine

homogeneous mixture

looks like a single substance
- example: air

heterogeneous mixture

appear to have two or more different-looking components
- example: dirt

compound

is a chemical substance that can be made by combining two or more other substances

elements

cannot be made from or broken down into anything else

hydrogen, helium, carbon, nitrogen, oxygen, fluorine, sodium, magnesium, aluminum, silicon

H; He; C; N; O; F; Na; Mg; Al; Si

manganese, iron, cobalt, copper, zinc, selenium, bromine, molybdenum, silver, tin

Mn; Fe; Co; Cu; Zn; Se; Br; Mo; Ag; Sn

atom

is the smallest possible piece of an element

atoms

are the basic building blocks of all matter
- are far smaller than anything we can observe with our senses

the mass of an atom

is an important property that is so small it is expressed in atomic mass units (amu)

subatomic particles

atoms are made of smaller objects called ______
- protons, neutrons, and electrons

proton

mass: 1 amu
- +1 has a positive charge

neutron

mass: 1 amu
- no charge

electron

mass: 1/1800 amu
- -1 has a negative charge

atoms

contains at least one proton and electron and most have neutrons

protons and neutrons; electrons

what makes up the nucleus and the space around

atomic number

the number of protons in an atom is called the

true

true or false; all atoms of a particular element has the same number of protons

the atomic number

what could be used to identify an element and is listed above the symbol for each element?

mass number

the total number of protons and neutrons in an atom is the

7

How many protons and neutrons are there in an carbon atom whose mass number is 13?

electrons

are arranged in electron shells or energy levels

each electron shell; the farther

has a limit to the number of electrons it can hold
- ____ from the nucleus, the more electrons the shell can hold

innermost shells

electrons prefer to occupy the ____ first since they are attracted to the nucleus

electrons

the ability of an element to form compounds and the formulas of those compounds are determined by the number of _____ in outermost occupied shells

2;8;18

- electron shell 1 electron capacity is ____ electrons
- electron shell 2 electron capacity is ____ electrons
- electron shell 3 electron capacity is ____ electrons

shell 1 has 2 electrons
shell 2 has 7 electrons

what would be the electron arrangement of fluorine?

orbital

electrons dividing themselves into pairs, each of which occupies a different region of the shell

shell 1: 2 electrons
shell 2: 4 electrons

the atomic number of carbon is 6. What is the electron arrangement in a carbon atom?

valence electrons

Electrons on the outermost energy level of an atom

true

true or false: elements that have equal numbers of valence electrons tend to have similar behavior

silicon and germanium: 4 electrons (similar behavior)
sulfur: six

how many valence electrons does each of the following elements have, and which two of these elements should show similar behavior?
Silicon
- shell 1: 2 electrons
- shell 2: 8 electrons
- shell 3: 4 electrons
Sulfur
- shell 1: 2 electrons
- shell 2: 8 electrons
- shell 3: 6 electrons
Germanium
- shell 1: 2 electrons
- shell 2: 8 electrons
- shell 3: 18 electrons
- shell 4: 4 electrons

Lewis Dot Structure

diagram of a molecule using dots to represent valence electrons

metals, metalloids, nonmetals

what are the three classes of elements?

metals

Elements that are good conductors of electric current and heat.
- can be bent and shaped

metalloids

are solids at room temp, are gray and look shiny when polished, conduct electricity poorly, are brittle and break instead of bending

nonmetals

elements that have variety of colors and do not look shiny when polished, do no conduct energy, are brittle and break instead of bending

11; 5; 1

____ nonmetals are gases, ____ are solids, and ____ (bromine) is a liquid at room temp

periodic table

lists the elements in order of atomic number, with the atomic number appearing above the symbol for the elements

period

a horizontal row of elements in the periodic table is called a
- are numbered from top to bottom

group

a vertical column of elements in the periodic table is called

Se, nonmetal

what element is in period 4 and group 6A? is this element a metal, a metalloid, or a nonmetal?

group number

the number of valence electrons in a representative element equals the

false

true or false: all elements in group 7A don't have seven valence electrons

true

true or false: for the transition elements (the "B" groups), the number of valence electrons does not equal the group number, and the relationship between the electron arrangements and the behavior of the elements is more complex

Sn - Group 4A and in fifth period
Valence electrons: 4
Valence electrons: shell 5

How many electrons are in an atom of tin (Sn, atomic number 50)? Which shell are they in?

isotopes

atoms of the same element that have different masses are called

atomic weight/mass

the periodic table does not list the individual isotopes of each element but an average mass of an atom of the element called

atomic weight

the average mass of an atom of that element
- appears below the symbol for the element in the periodic table

mole

a _____ of any element is the atomic weight of that element, expressed in grams. For example, the atomic weight of calcium is 40.08 amu, so a mole of calcium is 40.08 g of calcium

true

true or false: atoms are extremely small and light, so one mole must contain an enormous number of atoms

Avogadro's number

number of representative particles in a mole, 6.02214076 X 10^2

false

true or false: a mole of an element always contains different number of atoms

atomic weight: 24.31 amu
mole: 24.31 g

what is the mass of a mole of magnesium and how many magnesium atoms are there in 1 mole?

chemical formula

represents the specific ratio of atoms of each element required to form a compound

NaC5H8NO4

one formula unit of MSG contains one sodium atom, five carbon atoms, eight hydrogen atoms, one nitrogen atom, and four oxygen atoms. write the chemical formula of MSG.

formula weight/molecular weight

gives the weight of a single molecule of a compound, which is calculated by adding the atomic weights of all atoms

H: 1.008 amu
F: 19.00 amu
HF: 20.008 amu
Molar Mass: 20.008 g/mol

what is the formula weight of HF?