A
What has no mass and takes up no space?
light
What is the atomic number of neon?
10
Diet coke is a example of a homogeneous/heterogeneous mixture.
homogeneous
Fruit cake is a example of a homogeneous/heterogeneous mixture.
heterogeneous
What composes the nucleus of an atom?
protons and neutrons
You just won 500 points!
Yes you did! 500 points!
Define element.
An element is a substance whose atoms all have the same number of protons.
Define compound
Compounds are substances made up of two or more different elements that are chemically bound together.
How many significant figures (SF)? 0.0123
3
Ice floats on water because ...
H2O is less dense as a solid than it is as a liquid.
Define chemical energy.
Chemical energy is the energy which is stored in the bonds of chemical compounds.
What is the formula for density?
ρ=m/V
What is an ionic compound?
Ionic compounds form when a metal bonds with a nonmetal.
What is a covalent compound?
Covalent compounds form when nonmetals share electrons.
Is CaCl₂ ionic or covalent?
ionic
Is NH₃ ionic or covalent.
covalent
What is the formula for sulfur trioxide?
SO₃
What is the formula for potassium sulfide?
K₂S
What is the formula for carbon monoxide?
CO
What is the formula for tetraphosphorus hexaoxide?
P₄O₆
Balance the following equation.
HCl + CaBr₂ ⟶ HBr + CaCl₂
2HCl + CaBr₂ ⟶ 2HBr + CaCl₂
Balance the following equation.
HCl + Mg ⟶ MgCl₂ + H₂
2HCl + Mg ⟶ MgCl₂ + H₂
Balance the following equation.
CO₂ + H₂O → C₆H₁₂O₆ + O₂
6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂
Balance the following equation.
Na₃PO₄ + MgCl₂ ⟶ NaCl + Mg₃(PO₄)₂
2Na₃PO₄ + 3MgCl₂ ⟶ 6NaCl + Mg₃(PO₄)₂
Balance the following equation.
C₄H₁₀ + O₂ → CO₂ + H₂O
2C₄H₁₀ + 13O₂ → 8CO₂ + 10H₂O
Define physical change.
In a physical change, the material is chemically the same before and after the change and can usually be reversed.
Define chemical change.
In a chemical change, is any change that causes a new substance to be formed. Most are irreversible.
Write a balanced chemical equation for the decomposition of CsNO₃.
2CsNO₃ → 2Cs + N₂ + 3O₂
Write a balanced chemical equation for the formation of KHCO₃.
2K + H₂ + 2C + 3O₂ ⟶ 2KHCO₃
Write a balanced equation for the combustion of C₅H₁₀O.
C₅H₁₀O + 7O₂ ⟶ 5CO₂ + 5H₂O
How many grams are in a mole of gold, Au?
From the periodic table:
196.97 g/mole
How many moles of iron atoms, Fe, are in a 200.0 gram sample?
200.0 g ((1 mol Fe)/(55.8g Fe)) = 3.58 molFe
How many grams of CoCl₂ are in a 0.123 mole sample?
0.123 mol ((129.8 g CoCl₂)/(mol)) =16.0 g CoCl₂
An atom's chemistry is determined by ...
the number of valence electrons it has.
In an ionic compound, the metal (takes/gives) electrons, and the non-metal (takes/gives) electrons.
In an ionic compound, the metal (gives) electrons, and the non-metal (takes) electrons.
Which gas is responsible for absorbing and protecting us from gamma rays that come from the sun?
nitrogen
Where are the noble gases and how do they react?
The noble gases are in the column 8A and do not react to make compounds.
Name NH₄Cl.
ammonium chloride
Name Ca₃(PO₄)₂.
calcium phosphate
What are isotopes?
Isotopes are atoms with the same number of protons but different numbers of neutrons.
How many neutrons are in Li-8?
5 neutrons
Why is uranium enriched?
Uranium enrichment was used to convert uranium into a form that can be used in nuclear bombs.
Light behaves like a _?_ and a _?_.
wave and a particle
What color of light has the longest wavelength?
red
What color of light has a wavelength shorter than blue?
violet
When wavelength is large, frequency is _?_.
small
As a light wave's frequency increases, the energy _?_.
increases
In molecular geometry, what shape is a water molecule?
bent
Atoms are most stable in (higher or lower) electron orbit.
lower
Electrons can jump out of their orbits and ...
fall back down again
An isotope is considered radioactive when ...
its nucleus is unstable causing it to spontaneously decay.
What rays in the electromagnetic spectrum have the highest energy?
Where are cell phones on the electromagnetic spectrum?
Radio waves (long wavelengths)
This kind of bond is formed when atoms share electrons with significantly different electronegativity values.
polar bonds