CH 1-2
Boiling water is an example of a chemical or physical change.
Physical
Put 1023 in scientific notation?
1.023 x 103
What is the mass number of an element?
The sum of the protons + neutrons
What kind of compound is CCl4 (ionic, molecular, or acid)?
molecular
What is the molar mass of chlorine rounded to 2 decimal places?
35.45 g/mol
Is glucose (C6H12O6) a pure substance or a mixture?
Pure substance
0.0004509
What is the symbol notation for Oxygen-18?
188O
What is the name of BaBr2?
Barium bromide
How many molecules are in 51,000 moles?
3.1 x 1028 molecules
Is chocolate milk a homogeneous or heterogeneous mixture?
Homogeneous
How do you measure something?
Write down the numbers that are certain, then add 1 more digit that is uncertain.
Which scientist discovered the electron?
The one and only J.J. Thomson
What is the formula for trisulfur pentoxide?
S3O5
How many grams of carbon are equal to 2 moles?
24.01 g
What are the 4 steps of the scientific method?
1. Make observations, 2. formulate a hypothesis, 3. perform experiments, 4. draw conclusions.
Compare accuracy and precision.
Accurate is how close a single measurement is to the actual value.
Precision is how close several measurements are to each other.
Why is the plum pudding model of the atom incorrect?
It does not have a nucleus that contains protons and neutrons with electrons outside of it
What is the name of Cu3N4?
Copper (IV) nitride
The empirical formula of a compound is CH2. Its molecular mass is 70.00 g/mole. What is the molecular formula?
C5H10
The 4 indicators of a chemical change
1. release of a gas
2. production of light/heat
3. unexpected color change
4. formation of a precipitate (solid)
What is the density of an object that weighs 200 g and has a volume of 710 mL?
0.3 g/mL
The nucleus of the atom
What is the formula Cobalt (II) iodide?
CoI2
How many molecules of water are in 50 grams?
1.67 x 1024 molecules