Show:
Density
Physical vs. Chemical Changes
Elements, Compounds, and Mixtures
Periodic Trends
Types of Bonds and Counting Atoms
100
What is the formula for density?
Density = mass / volume
100
If a person were to break a glass container, would it be considered a physical or chemical change? Explain.
It is a physical change because its chemical composition was not changed. It is still glass.
100
NaCl - is this an example of an element, compound, or mixture? Explain.
Compound because there are two different elements chemically combined.
100
What is the least dense element of the halogens?
Fluorine
100
Count the number of atoms: 14NaHCl
Na = 14 H = 14 Cl = 14
200
What is the density of an object that has a mass of 20g and a volume of 10mL?
2g/mL
200
Melting is considered a physical change. Draw the particle arrangement that would represent melting.
(drawing) solid - > liquid
200
Draw an example of a mixture of compounds.
*Drawing*
200
Name the following groups: 1 14 18
1 - Alkali Metals 14 - Carbon Group 18 - Noble Gases
200
If Calcium bonds to Chlorine, what type of bond is it? Explain.
Ionic because metal bonding to nonmetal.
300
Draw a density column containing the following liquids: Karo Syrup (1.33g/mL); Rubbing Alcohol (0.75g/mL); and Vegetable Oil (0.91g/mL)
(top) Rubbing Alcohol (0.75g/mL) (middle) Vegetable Oil (0.91g/mL) (bottom) Karo Syrup (1.33g/mL)
300
If hydrogen gas combines with oxygen gas, it forms water. Is this considered a physical or chemical change? Explain.
It is a chemical change because it resulted in a brand new substance (water) that had different properties than both hydrogen gas and oxygen gas.
300
If two chlorine atoms bond together, would it be considered an element, compound, or mixture? Explain.
It is still an element because there are two atoms of the same element.
300
Which element has 6 valence electrons and 3 energy levels (rings)?
Sulfur
300
Explain what would happen if Sodium tried to bond with Argon.
Nothing because Argon is already happy with 8 valence electrons.
400
What is the mass of an object that has a density of 9g/mL and a volume of 9mL?
9 x 9 = 81g
400
What are the names of the 6 phase changes?
Melting, Freezing, Condensation, Evaporation, Sublimation, Deposition
400
Would the atmosphere be considered an element, compound, or mixture? What is the most common substance found in the air we breathe?
Mixture; Nitrogen
400
What is the most reactive metal in period 4? Explain.
Potassium because it's in Group 1 (most reactive metal group) and only needs to lose 1 valence electron to become stable.
400
Which element in Period 5 could form an ionic bond with Sodium (Na)?
Iodine because it is the only reactive nonmetal in Period 5.
500
What is the density of an object that has a volume of 10mL and a mass of 5g? Would the object float OR sink in water?
The object has a density of 0.5g/mL so it would float in water (density = 1.0g/mL).
500
If two different liquids cause a chemical reaction, sometimes a new solid is left behind that signifies a chemical reaction occurred. What one word describes this new solid?
Precipitate
500
What type of mixture is salt water considered?
It is a solution or a homogenous mixture.
500
How many protons, electrons, and neutrons are found in the isotope, Carbon-14.
Carbon-14 has an atomic mass of 14. Protons = 6 Electrons = 6 Neutrons = 8
500
Illustrate the bond between Gallium and Carbon.
This ionic bond should result in 4 Gallium atoms and 3 Carbon atoms.