Significant Figures
How many significant figures are in the following number: 103000
3
Calculate the mass of 59.3mL of aluminum. Aluminum has a density of 2.70g/mL.
160. g Al
What is an isotope?
each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons
Metal atoms tend to lose electrons to form positively charged ions known as _______ whereas nonmetal atoms tend to gain electrons to form negatively charged ions known as ______.
cations (Na+ in salt for example); anions (Cl- in salt for example)
Calculate the following problem and give your answer with the proper significant figures: (103 X 2.2)
230
How many feet per second is a car going if it travels a distance of 75 miles in 1.2 hours? (1 miles = 5280 ft)
92 ft/sec
The atomic number (Z) of an atom is equal to
the number of protons in an atom's nucleus and determines the atom's identity
What is the correct molecular formula for the compound, tetraphosphorus decaoxide?
P4O10
Calculate the following problem and give your answer with the proper significant figures: 1.5*10^2 + 4.2*10^7
4.2*10^7
the mass of a 5.00 grain aspirin tablet to milligrams (1 grain = 0.00229 oz) (1oz = 28.35 g)
325 mg
The mass number (A) of an element is equal to
the sum of the protons and neutrons in the atom
What is the formula for potassium sulfide?
K2S
(3.4/0.8) + (3.0 X 1.45)
9
Many chemistry conferences have held a 50-Trillion Angstrom (Å) Run. How long is this run in kilometers and in miles? (1 Å = 1 x 10-10 m) (2.54 cm = 1 in) (5,280 ft = 1 mi). Give answers in 2 significant figures.
5.0 kilometers or 3.1 miles
Determine the mass (in g) of 2.5 cups of water if the density of water is 1 g/cm3 and 1 cup = 240 mL
6.0 x 102 g H2O
When they are by themselves, Do the following elements exist as a molecule (diatomic), or as a single element? Na, N, F, O, Mg, K, H
Na, Mg, K: single element; N2, F2, O2, H2: diatomic elements
There are 20 people in a room, each at their own computer. Each person can type 120 words per minute. How many total words will the group type in 2.543 hours? Give your answer to 4 significant figures.
366200 words
A fence is 1,050. square yards. Each gallon of paint will cover 901.5 square meters of area. Unfortunately, the store ran out of gallons and is only selling paint by the liter. How many liters of paints will be needed to cover the whole fence in two coats of paint? (1 gallon = 3.785 L) (1 m = 3.280 ft)
7.376 L
Write both A/Z and symbol-mass formats for the following atoms:
Tyler will provide answer
Write a correct chemical formula for each of the following compounds:
Calcium Bromide, Aluminum Oxide, and Calcium Oxide
CaBr2, Al2O3, and CaO