Matter
How do you tell the difference between an element and a compound?
An element only has one type of atom (Br2), compounds have 2 or more different atoms (NaBr).
Calculate the number of protons, electrons, and neutrons an Mg cation that has a charge of 2+. The mass number is 25.
p=12 n=13 e=10
What color of light has the least energy?
red light
As the table progresses from left to right the elements become (more or less) reactive.
Less
Who is known as the father of the periodic table? When was the first model made?
Dmitri Mendeleev
1869
What type of change needs to occur to separate a mixture?
physical changes
Draw an atom of C-14
p=6, n=8, e=6 two electrons in first energy level, 4 in second each in a separate spot (no pairs)
Why do different chemicals emit different colors of light?
They have different electron configurations.
What is the name of the family in group 17?
Halogens
What is the difference between endothermic and exothermic?
exothermic releases energy (feels warm) endothermic absorbs energy (feels cold)
Give an example of a homogeneous mixture
chocolate milk, mashed potatoes with butter and cream, steel
Describe how you would calculate the average atomic mass of two isotopes: Cl-35, 75% abundant and Cl-37, 25% abundant
35(.75) + 37(.25)
What happens to frequency as wavelength increases?
Decreases by the same amount the wavelength increases.
How many valence electrons does a silicon atom have? What charge will it form when it becomes an ion?
4 valence electrons, charge of +4 or -4
How did Rutherford's gold foil experiment lead to the discovery of the nucleus?
When he shot alpha particles at the gold foil, most went straight through, but a few were deflected. This meant that they hit something very small, dense, and positively charged (because alpha particles are positive).
sodium chloride dissolves in water. Is this a physical or chemical change?
physical! you can evaporate the water (physical change) and get the salt back.
How many electrons can each sublevel hold? s, p, d, f
s=2, p=6, d=10, f=14
How did the atoms in the flame test lab produce light?
The electrons gained energy from the flame and jumped to a higher energy level. They released the energy in the form of light as they fell back down to their ground state.
List the following in order of increasing electronegativity: Zn, F, Na, He
He, Na, Zn, F
As explained by electronegativity, why are the noble gases so stable?
The noble gases possess a complete valence shell and do not usually attract electrons.
Alka-Seltzer gives off carbon dioxide when added to water. Chemical or physical change?
chemical change. CO2 is a new substance.
What is the electron configuration Krypton?
1s22s22p63s23p64s23d104p6
What is an emission spectrum? How does it differ from a continuous spectrum?
The emission spectrum shows bands of color that correspond to the amount of energy each electron is gaining and losing when the atom is excited. A continuous spectrum contains all the wavelengths of light.
Explain the relationship between the atomic radius and ionization energy and why it is that way.
When atomic radius increases, the electrons on the outer valence shell are farther away from the nucleus, so the protons and the electrons in the outer valence shell have less attraction between each other, making it easier to lose or gain electrons.
What two elements have an exception to the electron configuration filling pattern?
Chromium (Cr) and copper (Cu)