Conversion
How many millimeters are in 1 meter?
1000 mm
Which subatomic particle determines the identity of an element?
Proton
Is melting ice a physical or chemical change?
Physical
What type of bond forms when electrons are transferred between atoms?
Ionic
How many valence electrons does oxygen have?
6
How many significant figures are in 0.004050?
4
How many protons, neutrons, and electrons are in Na⁺? (Na mass is rounded to 23)
11 p, 12 n, 10 e
Is a reaction that releases heat exothermic or endothermic?
Exothermic
What is the formula of magnesium chloride?
MgCl₂
Draw the Lewis structure of H₂O. How many lone pairs are on oxygen?
2
Convert 3.5 × 10⁴ mg into grams.
35g
Write the electron configuration for phosphorus.
1s² 2s² 2p⁶ 3s² 3p³
How much heat is required to raise 10.0 g of water by 5.0°C? (In Joules)
209 J
Give the name of N₂O₄.
Dinitrogen tetroxide
Draw NH₃ and identify its molecular geometry.
Trigonal pyramidal
A metal has a mass of 54 g and a volume of 6.0 mL. What is its density?
9.0 g/mL
Which has the larger atomic radius, Na or Cl? Explain.
Na; radius decreases across a period.
A 50.0 g metal absorbs 450 J of heat and increases in temperature by 15.0°C. Calculate its specific heat.
0.600 J/g°C
Write the chemical formula for aluminum sulfate.
Al₂(SO₄)₃
(SO₄2-)
Draw the Lewis structure for HCN. Identify its molecular geometry and bond angle.
H–C≡N (nitrogen has one lone pair). Linear, 180°.
A medicine contains 20 mg per 5 mL. A patient needs 40 mg per dose, twice a day. How many mL of medicine will the patient take in one day?
20mL
An element has 20 protons, 22 neutrons, and 18 electrons. Identify the element, its mass number, and its ionic charge.
Calcium (Ca), mass number 42, charge +2 (Ca²⁺).
How much heat is released when 100.0 g of water cools from 80.0°C to 25.0°C? (In kJ)
23.0 kJ released
A compound contains aluminum ions (Al³⁺) and carbonate ions (CO₃²⁻). What is the correct chemical formula, and how many total atoms are in one formula unit?
Al₂(CO₃)₃ — 14 total atoms.
Question: Which of the following molecules is polar?
A. CO₂ B. CH₄ C. BF₃ D. H₂S
H₂S — Its bent molecular geometry prevents the bond dipoles from canceling.