Sig Figs
How many significant figures are in 15000?
2!
Define physical change
alters form or appearance without affecting chemical composition or bonding.
Define the difference between a heterogeneous mixture and a homogeneous mixture.
Heterogeneous mixt. = Not evenly distributed / different aliquots from different spots are different
Homogeneous mixt. = Evenly distributed / different aliquots from different spots are same
How many atoms are in 1 mole of atoms?
(Hint: Avogadro's number)
6.022E23
How many significant figures are in 16.000?
5!
Define chemical change
Substances change into 1 or more other substances, includes the formation or breakage of covalent bonds
Define the difference between an element and a mixture.
Element - 1 or more of the same element on the periodic table
Compound - more than one elements are bonded
Daily Double: Lucas is 5 ft 10 inches tall. How many coffee cups tall is Lucas if a coffee cup is 10.16 cm tall?
Hint: (1 in = 2.54 cm)
Lets go through this together on the board
Count significant figures in the answer using sig-fig rules. 15.01+1.0031=?
4! (16.01)
Which is a physical change and which is a chemical change?
Freezing of water H2O(l) -> H2O(s)
Formation of water 2H2 + O2 ->2H2O
Freezing = physical
Formation = chemical
Is this an element or a compound?
1. Balloon filled with Helium?
2. Cup filled with water?
1. Element
2. Compound
How many moles are in 103.2 g of CO2 (Carbon Dioxide)?
Lets do it on the board!
Count the significant figures in the answer using sig-fig rules.
9.57 * 150 = ?
2! (? = 1400)
Give an example of a physical change (not mentioned before in this session)
ex. chopping wood, breaking glass, dissolving sugar or salt in water...
Give one example of a homogeneous mixture and one example of a heterogeneous mixture
Homogeneous = well-mixed salt water, cookie dough, chocolate milk
Heterogeneous = chicken noodle soup, oil and water
Other options!
How many atoms of Nitrogen are in 57.67 g of Nitrogen?
Lets do it on the board!
Daily Double: Count significant figures in the answer using sig-fig rules.
(16.27 + 151.6)/(6.2 * 1.53) = ?
2! (? = 18)
Give an example of a chemical change
ex. soured milk, rotted fruit, digestion, photosynthesis
Label A, B, C, & D as element, compound, heterogeneous mixture, or homogeneous mixture.
Drawing Provided.
A = Heterogeneous mxt.
B = Element
C = Compound
D = Homogeneous Mixture
How many atoms of Oxygen are there in 124.56 g of CO2 (Carbon Dioxide)?
Let's do it on the board!