Physical vs
Chemical
Chemical
This type of change alters a substance's form (state) but not its composition.
What is a Physical Change?
Time
What is seconds (s)
Other SI Units?
Number of Sigs Figs 123.84
5
( What is the rule?)
If repeated measurements are tightly grouped together, they are:
What is precise
(Let's Talk about Accuracy)
Subatomic particles with no charge are located in the ( blank)
What is nucleus?
(Positive charge? Location?
Negative charge? Location?)
When iron rusts, this type of change occurs because new substances form.
What is a chemical change?
(what is the difference between chemical and physical change on a molecular level?)
Units for Density
What is mass/ volume or kg/m3
Number of sigs figs 0.00836
3
( What is the rule?)
A scale gives the weights 25.1 g, 25.1 g, 25.2 g, 25.1 g25.1 g, 25.1 g, 25.2 g, 25.1 g, but the true weight is 24.6 g24.6 g. These measurements are:
What is C. Precise but not accurate
(What does neither accurate nor precise look like?)
Substance 1: 18 protons, 23 neutrons
Substance 2: 18 protons, 25 neutrons
These are
What are isotopes?
(What is the element?)
Formation of gas, color change, and temperature shift are indicators of...
What is a Chemical change or reaction?
Length
What is a meter (m)?
Number of Sigs Figs: 12,000
2
(What if the comma was a decimal point?)
(What about accurate and precise?)
An element has the following natural abundances and isotopic masses:
72.15% abundance with 63.00 amu
27.45% abundance with 65.00 amu
0.40% abundance with 66.00 amu
Calculate the average atomic mass of this element.
What is 63.56 amu?
(Steps?)
Melting ice and burning wood both involve temperature changes, but only one changes chemical identity.
What is burning wood?
Amount of substance
What is mole (mol)?
Number of sig figs:1004
4
(What is the rule?)
If a balance is not zeroed correctly before use, this is (blank)
what is a systemic error
A bag of sugar weighs 2.5 lb. How many grams of sugar are in the bag?
1 lb=16 oz. 1 lb=454 g
What is 1135 g?
(Steps?)