Periodic Table
The periodic table is organized by what characteristic of an element?
It's atomic number - which is the number of protons found in the atom of an element
What is a pure substance made from only one type of atom?
An element
What is tin mixed with to make the alloy bronze?
Copper and tin make an alloy (mixture of metals)
80% of the periodic table are classified as...
metals
All matter is classified as either ___________ or ________________. Explain each.
Mixture (not chemically combined) or a pure substance (chemically combined)
How many periods and groups are there on the periodic table?
7 periods and 18 groups
How many Fe atoms in 4CO3Fe
4
Why are alkali metals, like Na, so reactive?
They have ONE valence electron to get rid of.
Solid, non-shiny & poor conductor elements are mostly classified as...
non-metals
Mixtures can be ______________ or _________________. Explain each.
Homogeneous (the mixture is uniform - the same throughout) or heterogeneous (mixture is different throughout)
What is an isotope?
An isotope is an atom that has a different number of neutrons.
Count the total number of atoms in this compound:
2Na(OH)3
14 total
The elements with the same properties are arranged in groups, families, or columns.
These elements are brittle and will break apart easily when someone attempts to mold them or bend them.
Nonmetals
Pure substances have unique physical and chemical properties. List 3 physical properties and 1 chemical properties you could use to determine the identity of a pure substance.
Physical: Color, luster, density, boiling/melting/freezing point, malleability.
Chemical: Reactivity, toxicity, etc.
Describe what is significant about the alkali metals and noble gases.
Alkali Metals: column 1 - all shiny metals, highly conductive, react instantly with water
Nobel Gases: column 18 - all inert gases/colourless/gases in natural state; very stable
What would you name the following combination of Li and O.
Lithium Oxide
What is carbon dating?
Carbon dating can be used to determine the relative age of an organism based on how much of a specific type of carbon is left. The less carbon-12, for example, the older the sample.
What is the name of the elements that are found around the descending staircase? What are their character traits?
Metalloids OR Semi-conductors
semi-conductive, appear to be metal but are brittle, have character traits of metals and nonmetals, usually are solid, often form alloys with other metals
Pure substances can be ______ or ________. Explain each.
elements (made up of one/same atom(s)) or compounds (made up of different elements)
Cl has two major isotopes: Cl-35 has an abundance of 75.78% and Cl-37 has an abundance of 24.22%, what is the average atomic mass?
What is 35.48 amu
Name and write the formula if Aluminum combined with Sulfur.
Aluminum Sulfide Al2S3
Only two elements came from the Big Bang, what were they?
Hydrogen and Helium
Explain one TREND on the periodic table as you move from left to right...
Elements become less metallic, less conductive, heavier, less reactive.
Explain how you would separate a mixture of salt, water, iron, and sand.
You could filter the iron/sand out from the salt water. Boil the water out of the salt and use a magnet to remove the iron from the sand.