UNIT 1 Lesson 1-3 Flashcards
TEST #1
List the 6 scientists, in the correct order who had contributions to the atom.
D, A, JD,JJT,ER,BR
1.Democritus
2.Aristotle
3.John Dalton
4.J.J Thompson
5.Ernest Rutherford
6.Bohr-Rutherford
What was Democritus’s theory?
Matter is made up of “atomos’ that could not be divided indefinitly.
What was Aristotle’s theory?
He modifed an earlier theory thta matter was made of four “elements” thereby delaying science
What was J.D’s theory?
4 points
1.All matter is made of atoms.
2.Atoms of an element are identical.
3.Each element has different atoms.
4.Atoms of different elements combine in constant ratios to form compounds.
Who am I?
I discovered electrons by doing an experiment using a cathode ray and some electrodes.
J.J Thompson
Who am I?
I discovered protons and nucleous by bombarding a sheet of gold foil with a stream of alpha (positive) particles.
Ernest Rutherford
Who am I?
I discovered orbitals/shells by observing how energy (heat) reacted with light and colour.
Bohr-Rutherford
What is the atomic number?
Its at the top of the symbol of the element. It is the number of protons in that element.
What is the difference between atomic mass and mass number?
Atomic mass= average mass of the atom (what is on the periodic table)
Mass number=calculated by rounding the atomic mass to the nearest whole number
True or False and why
number of Protons= number of neutrons
FALSE because #protons=#electrons
How do you find the subatomic particle: neutrons?
Mass number - #protons = #neutrons
protons also just means atomic number
Who organized the periodic table and how?
3 points
Dimitri Mendeleev, to classify the elements based on their properties: 1.periods and groups 2.solids,liquids and gases 3. metals, non-metals and metalloids
Period vs group?
Periods (horizontal row) indicates the number of shells/orbitals in an atom.
Groups ( vertical column) indicates the number of valence electrons. (electrons that exist on the outermost shell)
List the chemical families in the order they would be found in.
1.Alkali metals
2.Alkalines earth metals
3.Halogens
4.Noble/inert gases
What are the characteristics of Alkali metals?
4 points
- React violently when in contact with water (form a base/alkali)
- Only exist within a compound due to their high reactivity.
- Soft metals with low melting points.
- Excellent conductors of heat & electricity
What are the characteristics of Alkaline earth metals?
5 points
1.Grey metallic solids (often rocks)
2.Excellent conductors of heat & electricity
3.Harder in consistency than alkali metals
4.Less violent reactions than alkali metals
5.Similar chemical behaviour as alakli metals
What are the characteristics of Halogens?
5 points
1.MOST reactif/toxic non-metal (therefore only exist as compounds)
2.Found as either solids, liquids or gases
3.Combine with alkali metals to form salts (halogen = “saltmaker”)
4.Very colourful
5.Form strong acids when combined with hydrogen (ex. HCl)
What are the characteristics of Noble/Inert gases?
4 points
1.Exceptionally stable (= non-reactive, chemically inert)
2.Colourless in their natural state
3.Emit characteristic colours when in vaccuum tubes (ex. Neon)
4.They all are gases
Who am I?
I am found on the left of the staircase.
METALS
who am I?
I am found on the right of the staircase?
NON-METALS
who am I?
I am found along the staircase.
METALLOIDS
Explain the difference between a metal and a non-metal.
A metal can conduct heat and electricity, it is shiny and malleable. While a non-metal does NOT conduct heat and electricity, is not shiny and is brittle.
Describe a metalloid.
Is a combination of properties of metals and non-metals.
What is found on the shells of an atom and what is found in the nucleous?
Shells= e-
Nucleous= p+ and n*
