Download Atoms and Elements Class Notes and Class Work

Atoms and Elements Class Notes and Class Work
Introduction to Matter
Property: Characteristics matter has.
Law: A rule nature seems to follow. It’s been observed regularly.
Theory: Tries to explain the law
The Particle Theory of Matter
1. Matter is made up of particles (Atoms, molecules, and ions)
2. Pure substances: One kind of matter or particles ex. H2O (Water)
Impure substances: Two or more kinds of matter or particles. ex. Sugar + Water
3. All particles have an attraction to each other
4. Particles are in constant motion
5. Particles are not moving at the same speed
Class Work
1. What is a definition of “matter” and of “property”?
2. List three properties of matter to explain each of the following:
3. Use the particle theory of matter to explain each of the following:
a) Gases have low density (mass/volume)
b) Some substances are solids at room temperature.
c) Some substances have high boiling points.
d) Some substances are the same throughout.
e) An impure substance like sand and salt is not the same throughout
4. What is the difference between the law of gravity and the theory of gravity?
Lesson 2 - Physical and Chemical Properties
Physical Property: A characteristic that can be determined without changing a substance
into a new substance.
Quantitative Observation: involves measurement.
Qualitative Observation: Not involving measurement or numbers.
Chemical Properties: A characteristics that can only be determined when a substance is
changed into a new substance.
Class Work:
Read pages
Text Questions:
159 to 194
Page 188 (4,5,6,8 and 9) Page 289 (15,18,22,40)
Lesson 3 – Physical and Chemical Changes
Physical Change: a change in a substance with new properties being produces (without a
new substance). A physical change does not produce a new substance.
Chemical Change: an alteration in a substance in a substance in which a new
substance(s) is produced. , having new physical and chemical properties. (also know as a
chemical reaction)
Evidence that a chemical change may be taking place:
1. There is a change in temperature because heat energy is either being given off or
absorbed.
2. There is a permanent change in colour.
3. There is a formation of new odour.
4. Bubbles of gas are produced in the liquid after two liquid solutions are mixed.
5. A solid starting material gets used up.
6. A new substance with new properties appears to form.
Class Work:
Text Reading:
Text Questions:
p. 157-158; 169
p. 188 # 10 & 11
p. 290 # 23 a., b., & c.
1. Which one of the following is a physical change and which is a chemical change?
a)
b)
c)
d)
e)
f)
g)
h)
i)
The burning of rubber
The rotting of an apple
The melting of sodium chloride
The stretching of rubber
The crushing of a rock
The rusting of a machine
The burning of a match
The condensation of a gas to a liquid
The formation of hydrogen gas when hydrochloric acid is mixed with magnesium
2. State what evidence, if any, there is that a chemical change is taking place in each
of the following:
a) A gas condenses to form a liquid and heat energy is released.
b) When sodium hydroxide solution is added to hydrochloric acid solution heat
energy is released and sodium chloride and water are formed.
c) When an Alka-Seltzer is added to water there is much fizzing as carbon dioxide
gas is produced.
d) When sugar is added to water and the liquid stirred, the sugar disappears.
Name:
Date:
Lesson 4
Classification of matter
Matter
Homogeneous
Matter
Pure
Substances
Heterogeneou
s Matter
Mechanical
Mixtures
Solution
Ordinary
Mechanical
Mixtures
Element
Suspension
Compound
Colloid
Name:
Date:
Use arrows to match the words with definitions then place words in the flow chart above:
Matter
A heterogeneous mixture.
Homogeneous matter
A pure substance that is made up of two or more elements joined by
chemical bonds
Heterogeneous matter
Anything that has mass and occupies space.
Pure substance
A mechanical mixture whose parts are smaller than an ordinary
mechanical mixture.
Impure substance
Matter that contains only one kind of matter and one kind of particle.
Mixture
A mechanical mixture whose suspended particles are too small to be
separated by gravity.
Solution
Matter that is uniform or constant or the same throughout.
Mechanical Mixture
Matter that contains more than one kind of matter and more than one
kind of particle.
Suspension
Matter that is not the same throughout.
Colloid
Matter that is composed of two or more elements or compounds or
combinations of elements and compounds.
Ordinary Mechanical Mixture
Contains Large parts observable with the naked eye.
Element
A pure substance that cannot be broken down into other substances by
ordinary chemical means.
Compound
A homogeneous mixture.
Lesson 5- Discovery of Elements, their Symbols, and the Abundance
of elements
·
·
·
·
·
·
·
Elements have been known since ancient times.
By 1669 there were 14 elements known.
By 1860 there were approximately 60 known elements.
Today there are approximately 115 known elements.
Jakob Berzalius, A Swedish chemist devised the symbols for elements in 1814.
Usually single capitol letter or two letters with the second being a smaller letter.
Ex. Boron-B
Hydrogen-H
If two or more elements begin with the same letter you use two letters.
Ex. Hydrogen-H
Helium-He
·
Sometimes the first letter rule does not seem to be followed because it is based on
the Latin word.
Ex. Gold(Aurium)-Au
Potassium(Kalium)-K
·
The symbols for elements are universal.
·
Some elements are named after famous scientist:
Einstenium
Curium
Nobelium
·
Some elements are named after countries or states.
Polonium
Francium
Germanium
Californium
·
Lastly, some elements have been named after a special property they have or after
names in Greek mythology.
Helium-Helius
The Abundance of elements
· In our atmosphere (Dry air)
Nitrogen-N2 78.03%
Oxygen-O2 20.99%
Argon-AR 0.94%
Other trace amounts of: Xenon, Krypton, Helium, Neon and Compound CO2
The percentage composition of the most abundant elements in the earth’s crust and
atmosphere is:
Oxygen
O
49.20%
Silicon
Si
25.67%
Aluminum
Al
7.50%
Iron
Fe
4.71%
Calcium
Ca
3.39%
Sodium
Na
2.63%
Potassium
K
2.40%
Magnesium
Mg
1.93%
Hydrogen
H
0.87%
Titanium
Ti
0.58%
Chlorine
Cl
0.19%
Phosphorous
P
0.11%
Manganese
Mn
0.09%
Carbon
C
0.08%
·
The most abundant element in the Universe is Hydrogen(H)
Class Work
Text reading:
p. 190, 192, 198-200
Text questions:
p. 189 (#16)
p. 197 (# 1 a & b, 4, 5)
p. 214 (# 1, 2, 3)
p. 224 (#1, 6, 8)
Lesson 6- Model of the Atom
Atom: An atom is the defining structure of an element, which cannot be broken by any
chemical means. A typical atom consists of a nucleus with protons and neutrons, and
electrons circling this nucleus.
Nucleus: Is made up of neutrons (electronically neutral) and protons (positive charge),
collectively called nucleons.
Electrons: negatively charged subatomic particles
Sub-atomic particle Charge
Proton
+1
Neutron
0
Electron
−1
Since, under normal conditions, the atom as a whole is electrically neutral, the number of
electrons must equal the number of protons in the nucleus.
Neils Bohr model of the Atom:
· He compared the atom to the solar system:
· Nucleus is like the sun
· Electrons are like the planets circulating the sun.
Electron Shells: The fixed path or orbits in which the electrons travel around the
nucleus.
Example of the Bohr-Rutherford model:
The lowest energy level (first or innermost shell) can hold 2 electrons, the second energy
level (shell) can hold 8 electrons and the third energy level (shell) holds 8 electrons (with
10 in reserve).
Modern Models: The most modern model of the atom is called the Quantum mechanical
model or Wave mechanical model and was developed around 1952. It is more complex
than the Bohr-Rutherford model and is covered in High School.
Class Work:
1) In the Bohr model, what does the term “orbit” or “electron shell” mean?
2) Draw electron shell diagrams for:
a) O- 2 electrons in the first shell, 6 in the 2nd.
b) P- 2 electrons in the 1st shell, 8 in the 2nd, 5 in the 3rd.
c) Ge- 2 electrons in the 1st shell, 8 in the 2nd, 18 in the 3rd, 4 in the 4th.
3) Textbook questions: p.244 – 1, 3
p.254 – 3,4,8,9, 22, 23
p.289 – 14, 19, 29, 38
Lesson 7-Atomic Mass and The Periodic Table
Atomic Number: is the number of protons (which
equals the number of electrons) in each atom of the
element. For example, any atom that contains exactly
47 protons in its nucleus is an atom of silver.
Relative atomic Mass
Atomic Mass: the number of protons + the number of
neutrons in an atom. In the case of silver it would be 108 (47 Protons and 61 neutrons)
·
All the atoms of any particular element must have the same number of
protons(and therefore electrons). Hydrogen (with an atomic number of 1) for
example has one proton. But there is no reason why the number of neutrons can't
vary.
Isotopes: are atoms of the same element that have different masses. Meaning they have a
different number of neutrons.
·
In fact, there are three types of hydrogen atom, each containing a different number
of neutrons. We call these isotopes of hydrogen.
Look at the diagram below to see the isotopes of hydrogen. The two heavier isotopes of
hydrogen are often known as deuterium ( ) and tritium ( ).
·
Different isotopes of an element have the same atomic number (1), but different
atomic mass numbers.
·
Different isotopes of an element have different mass numbers, but react
chemically in exactly the same way.
Relative Atomic Mass: of an element is the average mass of the isotopes in a naturally
occurring sample of the element, taking into account the proportion of each isotope
present.
The Modern Periodic Table (p. 562 in your text)
Modern Periodic Law: States that when elements are arranged in order of increasing
atomic number, elements with similar properties occur at regular intervals. (Sometimes
every 8 or 18 etc.) i.e. Elements with similar properties occur periodically.
The State of Elements:
· Most elements are solid at room temperature
· A few elements are liquids such as Bromine and Mercury
· A small number are gases such as hydrogen, nitrogen, oxygen, fluorine, chlorine,
and group 18 noble gases (see below)
Classification of Elements: Elements can be classified as metals, non-metals or
metalloids.
Classification
Physical
properties
Chief chemical
properties
Metals
· have lustre
· good conductors of
heat and electricity
· malleable(can be
hammered)
· ductile (can be
drawn into wire)
Lose or give up
electrons easily
Non-Metals
The opposite of
metals
Gain or accept
electrons easily
Metalloids
Some properties of
Metals and some
properties of nonmetals.
Where are metals , non-metals and metalloids found in the periodic table?
The Periodic table has:
· elements placed Horizontally (rows or periods)
· elements placed vertically (columns or group)
Elements in the same column or group have similar properties and are called a Family.
· Group 1: Alkali metal family- React with water to produce hydrogen gas and
other products
· Group 2: Alkaline earth metal family· Group 17: Halogen family
· Group 18: Nobel gas family
As you go down groups 1 and 2 the metals are more reactive.