Chapter 1
What is matter?
Anything that has mass and takes up space.
What is a pure subsance?
a substance whose properties are the same throughout
What is an element
A collection of atoms that all have the same number of protons
What is wave particle duality
The concept that light as well as many subatomic particles have the properties of both particles and waves
What is a covalent bond
a chemical bond that is made by sharing electrons
What do we use to measure a graduated cylinder
The meniscus
Is this an element, compound, heterogenous mixture, homogenous mixture.
A bowl of fruit covered with yogurt
Heterogeneous mixture
All atoms have an equal number of what?
EQUAL number of protons and electrons
What is the current model of the atom
Quantum mechanical model
List all the homonuclear diatoms
Hydrogen, nitrogen, oxygen, fluorine, chlorine, bromine, and iodine
How many sigfigs are in these numbers?
1. 106mL
2. 0.00067000 in
3. 3.400 kg
1. 3
2. 5
3. 4
A student does a chemical reaction with two chemicals. The total mass of the two chemicals is 17.0 grams. When she is done, she finds that the mass of all the chemicals she has collected is now 17.8 grams. The teacher says the student obviously contaminated the experiment with something else. How does the teacher know this? What is the mass of the contaminants?
She has some contamination, because the Law of Mass Conservation says the mass cannot change. The mass is 0.8 g. Since there is more mass now, something had to be added during the course of the experiment. Since she started with 17.0 g, she should only have 17.0 grams at the end. The excess (0.8 g) is the mass of the contaminants.
What is the crest and trough of a wave?
The highest and lowest point of a wave
In order to come up with his model of the atom, Erwin Schrodinger analyzed the electrons as if they were
Waves
Name the following molecules:
a. CaCl2 b. N2O c. SO3 d. N2O4 e. C2Cl2
a. This one is there to keep you on your toes. You don’t use prefixes, because this molecule has a metal and nonmetal and is therefore ionic. Thus, it is calcium chloride. b. There are two nitrogens and one oxygen, so it is dinitrogen monoxide. You can also say dinitrogen monooxide. c. There is one sulfur and three oxygens. We drop the “mono” prefix for the first element, so it is sulfur trioxide. d. There are two nitrogens and four oxygens, so this is dinitrogen tetroxide. You can also say dinitrogen tetraoxide. e. There are two carbons and two chlorines, so this is dicarbon dichloride.
An object has a length of 3.45m, what is its length in inches?
136 inches
Which two of the following atoms would be isotopes? a. An atom made of 11 protons, 12 neutrons, and 11 electrons b. An atom made of 11 protons, 11 neutrons, and 11 electrons c. An atom made of 12 protons, 12 neutrons, and 12 electrons d. An atom made of 12 protons, 12 neutrons, and 12 electrons
Choices (a) and (b) are isotopes. Isotopes must be from the same element but have different numbers of neutrons. Thus, they must have the same number of protons. Choices (a) and (b) have the same number of protons but different numbers of neutrons. That makes them isotopes. Choices (c) and (d) have the same number of protons but also the same number of neutrons and electrons. They are identical atoms, not isotopes.
Longest: Red
Shortest: Violet
Give the ground state electron configuration for
A. Nitrogen
B. Aluminum
C. Magnesium
D. Bromine
A. 1s^2 2s^2 2p^3
B. 1s^2 2s^2 2p^6 3s^2 3p^1
C. 1s^2 2s^2 2p^6 3s^2
D 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^5
6. Order the following atoms in terms of increasing size: O, Cs, Al, Ca
Size decreases as you go up and to the right on the Table, so the element highest and farthest to the right is the smallest, and those that appear farther down and to the left are larger: O, Al, Ca, Cs.
Silicon has a density of 2.3 g/mL. What is the volume of a silicon block that has a mass of 1.72 kg?
Volime = mass/density
1.72kg x 1000 = 1,720g
1,720g/ 2.3 g/mL = 750mL
. A chemist combines 30.00 grams of silicon with 32.00 grams of oxygen. The result is 60.09 grams of a solid and some leftover silicon. How much silicon and oxygen should she use to make 150.00 grams of the solid with no leftovers?
70.11 grams of silicon must be reacted with 79.87 grams of oxygen.
First, we need to find out the mass of leftover silicon so we know the correct recipe. I
nitial mass = 30.00 g + 32.00 g = 62.00 g
Mass of leftover silicon = 62.00 g – 60.09 g = 1.91 g
Actual mass of silicon used: 30.00 g – 1.91 g = 28.09 g
That means the actual recipe is 28.09 g + 32.00 g. Now we just need to scale up:
Factor = 150.0g/60.09g = 2.496
Mass of silicon = 2.496×28.09 g = 70.11 g
Mass of oxygen = 2.496×32.00 g = 79.87 g
What is spetroscopy
Identifying chemicals by studying the light they emit or absorb.
Draw the Lewis Structure for Oxygen
O with six dots, two above, two to the side, one on the bottom, and one to the side
7. Order the following atoms in terms of increasing electronegativity P, Ga, O, Rb, Ca
Electronegativity increases as you go to the right and up, so the one farthest down and to the left is the least electronegative, and those farther up and to the right are more electronegative: Rb, Ca, Ga, P, O.