Sig-fig & Atomic Structure
how many significant figures: 97
2 sig-figs
How many mL (milliliters) are in 1 L (Liter)?
1000 mL
Mass = 31 g. Volume = 20 mL. What is the density?
1.6 g/mL or 1.55 g/mL
What is the formula for percent error?
Experimental Value-Theoretical Value
Divided by theoretical value
x100
Which subatomic particle has a positive + charge?
Protons
how many significant figures: 7.70
3 sig-figs
How many grams are in a kilogram?
1000g
The half-life of Calcium-40 is 2.0 hr. How much of a 40.0 g sample of this isotope remains after 6.0 hr?
5.0g
Is the data 123, 120, 121 percise? Yes or No
Yes, it is precise
What is the symbol for Iron?
Fe
The name of the subatomic particle that has 0 charge
Neutrons
100cm
The half-life of Silicon-28 is 3.0 hr. How much of an 80.0 g sample of this isotope remains after 15.0 hr?
2.5 g
If the actual number is 32, are the data points 24, 7, 92, accurate?
No they are not accurate
The mass number represents the combonation of
_____ + _____
Protons & Neutrons
There are two isotopes. One has an abundance of 7.30% and a mass of 6.017 amu. The other has an abundance of 92.70% with a mass of 7.018 amu. What is the average atomic mass?
6.94 amu
Conver 25 cg into kg
0.00025
An object has a mass of 21.0 g and displaces 10.3 mL of water. What is the density of the object?
2.04 g/mL
If the actual value is 121, the data found is 123, 120, 122. High/poor accuracy? High/poor precision?
High Accuracy and High Precision
Isotopes have the same number of protons, but a different number of ________________.
Neutrons
There are three isotopes. One has a mass of 46.0 amu and an abundance of 18.3%. Another has a mass of 47.0 amu and an abundance of 61.2%. The third one has a mass of 48.0 amu and an abundance of 20.5%. What is the average atomic mass?
47.02 amu
Convert 2.0 m into cm (move decimal)
200 cm
There is 15.5 mL of water in a graduated cylinder. When measuring the mass of a cube, it came out to be 35.0 g. The cube is added to the graduated cylinder, the water level rises to 25.6 mL. What is the density of the cube?
3.47 g/mL
The theoretical amount of Iron was 0.846 grams. The experimental value was 0.698 grams. What is the percent error of this reaction?
17.5%
If Chlorine has a mass of 37 amu and it has 17 protons. How many neutrons does it have?
20 neutrons