GRADE 8 / SCIENCE / TERM 1 /Atoms & Elements
Describe the main groups which are found in each vertical column on periodic table ...
>They are numbered 1-7 >Last group on the right is 0
Description of a Diamond
>Transparent and colorless >Hard but brittle *Can be shattered
What is a ductile material?
A material that can be pulled out into a long wire.
What does GROUP 1 on the periodic table represent?
Alkali Metals
Al
Aluminium (used for transport, packaging and construction)
Ar
Argon
Are elements in the same group similar?
Yes
Are groups in elements similar?
Yes. >Each row has similar elements lined up in a vertical column >This is know as the periodic table.
Zn
Zinc (used in alloys such as brass, nickel and silver & aluminum)
What are the symbols of elements made of?
letters of the alphabet
Where are metals, non-metals and Hydrogen located on he periodic table?
metals > letft non-metals > right hyrdrogen > middle
What is the smallest indivisible particle that is made of elements?
Atom
What is the smallest particle?
Atom
Location of Atomic #, Mass # & Symbol
Atomic #, Mass # & Symbol
What number describes the # of protons and also the position of the periodic table?
Atomic Number
Be
Beryllium
B
Boron
Br
Bromine (used for water treatment in swimming pools and hot tubs to prevent algea and bacteria growth)
Ca
Calcium (used as an alloying agent for aluminum, copper, lead and magnesium)
What is a Malleable material?
Can be rolled in flat sheets
C
Carbon (Diamond: used as abrasive & Graphite: used in brake linings; gaskets and clutch materials)
What are compounds?
Chemicals made from atoms and different elements joined by chemical bonds.
Cl
Chlorine
Calcium
Compounds of this metal are essential for healthly bones and teeth.
Barium Sulphate
Compounds of this metal are used in hospital scans to help show digestive systems clearly on an X-ray.
Who is the Russian Scientist that arranged teh elements in order of Atomic Mass from lightest to heaviest?
Demitri Mendeleev
What is a chemical property?
Describes how elements + other elements = compounds
What is the hardest natural substance on earth?
Diamond
What is a compound made of?
Different kinds of atoms
Copper
Electrical Cables.
What are the building blocks of all substances? *It cannot be broken down by physical or chemical changes
Element
What are found on the periodic tables?
Elements
A chemical property can be observed without changing the substance into another substance.
False.
An element can be broken down into a simpler substance.
False.
Non-metals can break apart easily and are said to be brittle.
False.
One property of metals that make them suitable for use as cooking posts is that they are good conductors of electricity.
False.
Steel/Brass.
Fishing weights.
F
Flourine
What do vertical columns on he periodic table represent?
Groups
What does GROUP 3 on the periodic table represent?
Halogens
He
Helium (used to inflate blimps and scientific and party balloons
What is a chemical reaction?
How elements change when they are combined. Example: Fe + S = Iron sulphite black + yellow = grey black
H
Hydrogen (*used to create water & metallic reduction)
What does GROUP O on the periodic table represent?
Insert Gases
Which element is attracted to magnets?
Iron
Fe
Iron (used ot manufacture steel)
Which English Scientist discovered that each element has its own atom?
John Dalton
What does brittle mean?
Light
In what order did Mendeleev arrange the elements?
Lightest to heaviest atomic mass.
Li
Lithium
What is total # of protons + total # of neutrons called?
MASS #
Mg
Magnesium (used in incedniary bombs)
Gold
Making Jewelry.
Steel/Aluminum
Making buildings.
What is particle theory of matter?
Matter is made from particles or (atoms) and atoms are too tiny to be seen by the eye.
Are most elements metals or non-metals?
Metals
What does the Zig Zag line on the periodic table separate?
Metals from Non-metals
What are the 3 categories the periodic table is divided into?
Metals, non-metals & metalloids
When mixing elements, do their properties change?
NO.
Ne
Neon
N
Nigtrogen (make up 78% of earth's atmosphere. Can be used to replace aire and reduce oxidation of materials)
When we use common metals and non-metals, are they normally in their "pure element form"?
No. We use them mostly as ALLOYS OR COMPOUNDS (with other metals and non-metals)
How many atoms does a substance have?
One
O
Oxygen (helps us breathe air)
What do horizontal rows on the Periodic table represent?
Periods
P
Phosphorus
The characteristics of a substance that can be observed without changing it into another substance is called?
Physical property
K
Potassium (used in fertilizers and salt substitute)
What does periodic mean?
Repeated at regular intervals
Si
Silicon
NA
Sodium (used in street lights)
S
Sulphur (used in the creation of shell and rubber)
What is conductivity?
The ability of an object to transfer electricity
Copper, which is ductile, is usually used to make electrical wires.
True.
Non-metals generally have low densities.
True.
How are elements lined up on the periodic table?
Vertically
How can physical properties be examined?
>Observing an element >Heating of cooling >Applying force until it bends or snaps
Description of Graphite
>Opaque >Black and soft >Conducts electricity
What is unusual about Steel and Mercury? (both metals)
>Steel is magnetic >Mercury is the only liquid metal @ room temperature
What are the properties of non-metals that are solid @ room temperature?
1/2 are solid, 1/2 are gases (1) is a liquid (bromine).
How many elements are listed on the periodic table?
117
On the periodic table how are the elements categorized?
>Atomic number >Structure >Properties >Mass Number
In what two forms does pure carbon exist?
>Diamonds >Graphite
Name 3 metals that are magnetic
>Iron >Cobalt >Nickel
What is luster?
The way a substance reflects in the light
What are chemical bonds?
These are formed when atoms transfer or electrons are shared.
Mercury
This is a liquid metal found in thermometers.