Atoms
How many phosphorus atoms are represented in the formula for Sr3(PO4)2
2
Which of the following represents a physical change:
Tearing
Ripping
Pruning
Burning
Tearing, Ripping, pruning
Where are the reactants found in a chemical equation
left side
Write the formulas that are found on density triangle
d=m/V
V=m/d
m=Vxd
Which of the following is evidence of a chemical change:
substance dissolving
bubbles forming
sinking to bottom
floating
bubbles forming
Na2SO4. How many sulfur atoms are in the formula
for sodium sulfate?
Photosynthesis is the process of plants creating food. Is this a chemical or physical change
Chemical Change
What is found on the right side of a chemical equation
products
What is the density of a rock that has a volume of 10mL and a mass of 37.5 grams.
D= 3.75 g/cm3
What does displacement method help us calculate
volume of irregular shaped object
How many atoms are in the following chemical formula:
3H3(P2F)4
9-Hydrogen
24- Phosphorus
12-Flourine
Which of the following is what occurs when salt is dissolved into hot water:
physical change that cannot be reversed
physical change that can be reversed
chemical change that cannot be reversed
chemical change that can be reversed
physical change that can be reversed
CaCO3 → CaO + CO2
A student heated 25 g of CaCO3. After the reaction, they measured 14 g of CaO.
What was the mass of the CO2 gas that escaped during the reaction?
11 Grams
What is the density of an unknown sample if it has a mass of 14.5g and a volume of 2.5mL
5.8g/cm3
Which of these is the best evidence that a chemical reaction occurs when coal
burns?
The shape of the coal changes.
Oxygen is present.
A new substance is produced.
Coal is made up of more than one element.
New substance is produced
Which formula has the most Hydrogen atoms:
C2H6O
C8H18
CH3CH2Br
C4H10O
C8H18
Which of the following is evidence of a chemical change?
a gas is present
atoms remained unchanged
colored gas is produced
the state of matter changes (solid, liquid, gas)
Colored gas is produced
What does the arrow represent in a chemical equation?
that they are equal or have undergone a chemical reaction
What is the density of an object that has a volume of 23.1 mL and a mass of 25g. Round to the hundredths place
1.08 g/cm3
find the density of a cube that has sides of 3cm and a mass of 27 grams
Boron Sulfate, B2(SO4)3 . Boron atoms represented by blue beads, sulfur atoms by yellow beads, and oxygen atoms by green beads.
2 Blue (Boron), 3 Yellow (Sulfur), 12 Green (Oxygen)
List the 5 ways to know a chemical reaction has taken place.
color change, bubbles/gas, light, temperature, precipitate
What does it mean for a chemical equation to be balanced?
there are the same number of atoms of each element on both the product and reactant side of the equation
If a graduated cylinder measured 20mL of water and a substance was placed into the cylinder and it is now 32mL. What is the volume?
V=12mL
Which observation
would provide the best evidence that a chemical reaction occurred?
The baking soda and hydrochloric acid combined, and bubbles formed.
The baking soda absorbed the hydrochloric acid.
Some of the baking soda dissolved in the hydrochloric acid.
The hydrochloric acid evaporated, leaving only the baking soda.
bubbles formed