Elements, Compounds, and Mixtures
Solids, Liquids, and Gases
The Atom
The Periodic Table
Chemical Bonds
100
Milk is an example of a(n) __________________
Mixture
100
Which phase of matter has particles that move the fastest and are spread farthest apart?
Gases. "Phase," "Phase of matter," and "State of matter" all refer to solids, liquids, and gases
100
This is the least massive of the three subatomic particles.
The electron! It's so light that we don't count it in our calculation of atomic mass.
100
The Periodic Table is arranged in order of increasing... a. Mass b. Atomic number c. Oxidation number d. Atomic radius
b. Atomic number The table is almost arranged in order of increasing mass, too, but there are several "out of order" elements.
100
Which family of elements on the Periodic Table are chemically unreactive?
Noble gases. They are happy with their full valence shells already!
200
How many different elements make up the compound Na3PO4? How many total atoms are in the compound?
3 elements (sodium, phosphorus, oxygen) and a total of 3+1+4=8 atoms
200
Gases turn into liquids through this process.
Condensation. It's opposite--liquid to gas--is evaporation.
200
This subatomic particle determines the identity of an element...always!
The proton. The atomic number is equal to the number of protons...always!
200
The elements in the halogen family have how many valence electrons?
7. The halogen family is group 17. Valence electrons are in the outermost shell, so it is written as the last number in the electron configuration on your Periodic Tables.
200
Name three elements that are likely to react in chemically similar ways.
Any three elements that are members of the same family/group (column on the Periodic Table). Atoms with the same number of valence electrons are likely to act in chemically similar ways.
300
Explain why Br2 is an element, not a compound.
It is only made up of one type of atom, and compounds are made of at least 2 different types of atoms.
300
Draw and label particle diagrams of a solid, liquid, and gas.
Solid particles should be tightly packed; liquid particles should "flow" with minimal space (still has a clear shape); gas particles should be widely spaced
300
Electrons orbit the nucleus in ___________________.
Energy levels, shells, or orbitals...all are great answers!
300
How many electron shells does the element in group 3, period 5 have?
5
300
Give three examples of elements that are likely to loan (give away) electrons in a chemical bond
Any three metals! In ionic bonds, metals tend to give away electrons to nonmetals. Remember, anything left of the black staircase on the Periodic Table (except hydrogen) is a metal.
400
Describe why salt water is classified as a homogeneous mixture, but oil and water is classified as a heterogeneous mixture.
Salt water all looks the same (looks like one thing), while oil and water looks different (looks like two different things). In more scientific terms, the particles of salt water are evenly distributed while the oil and water particles do not mix.
400
Temperature is a measure of this three-word term describing how fast particles move.
Average kinetic energy! The higher the temperature, the faster the molecules move--that movement is an increase in kinetic energy.
400
This scientist was the first to theorize that electrons orbited the nucleus in circular orbits.
Niels Bohr. This is the model we most often use to show electron configuration.
400
Name two elements that you would expect to have properties of both metals and nonmetals.
Any of the following 7 elements are classified as metalloids (or semi-metals): B, Si, Ge, As, Sb, Te, At. Metalloids have some properties of metals and some of nonmetals, often making them useful for building electronics.
400
What are the names of the following 2 compounds: MgBr and NaF?
Magnesium bromide and sodium fluoride. If the anion (negatively charged, second half of compound) is off the Periodic Table, change the ending to -ide.
500
Why is NaCl(s) classified as a pure substance while NaCl(aq) is classified as a mixture?
NaCl(s) is solid sodium chloride (a homogeneous compound), while NaCl(aq) is sodium chloride dissolved in water (a homogeneous mixture).
500
Name the two phase changes during which potential energy is increasing.
Melting and evaporating--heat is being added during both of these phase changes, but temperature does not change.
500
This scientist came up with the modern model of the atom that says we can't know exactly where electrons are, just where they probably (or most likely) are.
Ernest Schrodinger. We did a mini-lab where you counted lentils/peas on a paper target that showed we can't know exactly where an electron will be found, but we can predict where it is most likely to be.
500
I was handed a small sample of a nonmetal. What are three characteristics that you would expect it to have?
Any of the following; no metallic luster, no electrical conductivity, brittle (if solid), does not react with acid, could be a solid, liquid, or gas
500
Write the formula for the neutral compound that would be formed when calcium and chlorine ions join up.
CaCl2. Two -1 charged chlorine ions are needed to cancel out the +2 charged calcium ion.
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