Scientific Method, Classifying Matter, Physical and Chemical Properties and Changes
What is chemistry? What is matter?
The study of matter and matter is anything that has mass and takes up space.
A cube has a mass of 150 g and a volume of 25.0 cm³. Calculate its density.
6.00 g/cm3
What charges do protons, neutrons, and electrons have respectively?
Positive, neutral, negative.
What's the difference between bonding pairs, lone pairs, and non-bonding pairs?
Bonding pairs connect elements, lone pairs are on the central atom, and non bonding pairs are on the outside.
What's the difference between a mixture and compound? Give an example of each.
A mixture can be separated by physical memthods while a compound is a combination of two or more elements that can't be separated through physical methods. Mixture: gatorade, compound: NaCl
How many significant figures are in the measurement 0.02540 g?
4
Write the abbreviated configuration for Te (element 52)
[Kr] 5s2, 4d10, 5p4
Explain the main difference between an ionic, covalent, and metallic bond.
Ionic: transfer of electrons, covalent: sharing of electrons, metallic: move freely among a lattice
Is rusting a physical or chemical change?
Chemical
In a river delta, sediment cores show that 1.26 meters of clay has accumulated over the last 8,400 years. A geoscientist divides the thickness by the time to estimate the sedimentation rate. What is the sedimentation rate in cm/year, reported with the correct rounding and number of significant figures?
0.015 cm/year
What is the maximum number of electrons that can have the quantum numbers n=3, l = 2?
10
What type of bond is NaCl?
Ionic
If a chemical is made in a lab, it must be less safe than the same chemical found in nature. Is this statement true?
No, safety depends on structure, dose, and exposure.
A child weighs 44 lbs. The recommended dose of a liquid medicine is 10 mg/kg of body weight. The child must take two doses in one day. The medicine bottle says 1 teaspoon (tsp) contains 100 mg of the drug. How many teaspoons of medicine should the child receive for the entire day? (1 kg = 2.205 lbs, 1 tsp = 5.0 mL)
4.0 tsp total
Which element has the valence electrons 4s² 3d¹⁰ 4p5?
Bromine
Draw the lewis structure for SF-
Drawn on board
Name the five major fields of chemistry
Inorganic, organic, analytical, biological, physical
A vetrinarian needs to sedate a large cat weighing 120 lbs. The recommended anesthetic dose is 4.5 mg/kg of body weight per hour. The cat must remain sedated for 3.0 hours. The anesthetic solution has a concentration of 15 mg/mL. How many milliliters of the anesthetic solution are required?
(1 kg = 2.205 lbs)
49.0 mL
Which element has the largest atomic radius: Li, Be, Na, or F? Which has the highest ionization energy?
Largest radius = Na, highest ionization energy = F
Draw the lewis structure for CO-23
Drawn on board