Unit 1
How many centimeters are in one meter?
100 cm.
Which one has the smaller amount? solvent / solute.
solute
What subatomic particle does not account for an element's atomic mass?
Electrons
What is the group number for halogens?
Group 17
What is the prefix that means “four” in naming covalent compounds?
tetra-
What’s the difference between volume and density?
Volume is the amount of space an object takes up. Density is the amount of matter in the space.
Define homogeneous and heterogeneous.
Homogeneous: evenly distributed
Heterogeneous: unevenly distributed
What is the number of waves that pass through a single point in 1 second measured in?
Frequency
Why can’t noble gases bond with other elements?
The outermost shell is already full
Name this compound: Sn(SO₄)₂
Tin(lV) Sulfate
Find the density of an item with a volume of 150mm^3 and a mass of 300g.
2 g/mL
What is the law of conservation of matter? Give an example.
Matter cannot be created nor destroyed, only changed.
Burning wood, melting ice, dissolving sugar in water, etc.
What is the relationship between the frequency of a wave and its wavelength? Explain briefly.
The shorter a wavelength the higher the frequency, because more wave cycles must pass by per second to keep its speed.
What is the electronegativity value and bond between F and H?
1.9 and Ionic Bond
Write the chemical formula for a compound with Al with a charge of 3+ and F with a charge of (1-).
AlF₃
Mr. Kim fills a graduated cylinder with 33.2 mL of water. He then carefully drops in an eraser and the water level rises to 47.8mL. If the mass of the eraser is 98.6g, what is the density of the eraser? (Round to the nearest significant figure)
6.75g/mL
What is the difference between mixtures and compounds?
Mixture: matter made up of substances (element or compound)
Compound: substance made up of elements
Or
Mixture: physically combined together
Compound: chemically combined together
What is the dual nature of waves?
The dual nature of waves means electromagnetic waves can act as both particles and continuous waves, depending on how they are observed. They show wave properties but can also act as particles called photons while interacting with matter.
Explain the trend for electronegativity and explain why it occurs.
Electronegativity increases from left to right and decreases from top to bottom because atoms with more protons pull electrons more strongly, while larger atoms with more shielding pull less strongly.
Explain the differences between sulfide and sulfate.
Sulfide contains only sulfur, while sulfate is more stable and contains both sulfur and oxygen.
Mr. Kim has 144 apples and sells them for 3 apples for a mango. He then exchanges these mangoes for 4 mangos for a peach, and then sells them for watermelon. Each watermelon is worth 2 peaches. He then cuts each watermelon into 6 slices to share with his Chemistry class. How many watermelon slices are there?
36 slices
Are these physical changes or chemical changes? And explain how to distinguish each of them.
melt, explode, burn, crush, bake
Chemical:
explode (new substances are formed, like gas and ash)
burn (it’s a reaction with oxygen and also forms new substances)
bake (cake ingredients forming new substances)
Physical:
Melt (water and ice are the same substance, just a different state)
Crush (only changes size/shape. The material is still the same)
What is the same of all radiant waves, explain why?
They all travel at the speed of light because radiant waves travel in photons which are massless, and any massless particle regardless of energy level must travel at the maximum speed, the speed of light.
What is shielding, and explain how it works. Include the words Nucleus, Attraction, Repulsion, and Outer Electrons.
Shielding occurs when the inner electrons cause repulsion that reduces the attraction between the nucleus and the outer electrons.
What is the difference between naming an ionic compound with transition metals and a covalent compound?
In ionic compounds with a transition metal, Roman numerals are used instead to represent the exact charge of the transition metals. In covalent compounds, prefixes are used to indicate the number of atoms of each element.