Vocabulary
the smallest unit of an element
What is atom
How many atoms are in the compound NaCl?
What is 2
Two substances are combined together in a beaker. Which of the following observations would most likely indicate that a chemical reaction has occurred?
a. gas bubbles are produced
b. one substance sinks to the bottom of the beaker
c. the two substances remain mixed together
d. one substance dissolves in the other
What is gas bubbles are produced
What happens to atoms in a chemical reaction?
What is they are rearranged
If the combined mass of two reactants is 10 grams, how much mass will be present in the products?
What is 10 grams
How many atoms are in the compound Ba(OH)2
What is 5
Two different liquids are combined into a beaker and bubbling occurs. What can be concluded about the two liquids?
a. both liquids cooled when mixed
b. filtering would make it possible to separate the liquids
c. a chemical reaction occurred between the two
d. a new substance with the same properties as the original liquids formed
What is a chemical reaction occurred between the two
We know an endothermic reaction has occurred what the surrounding temperature ___________
What is decreases
If two substances were combined in a beaker, how would you know a chemical reaction took place?
a. new substances were created
b. one substance dissolved in the other
c. one substance melted in the other
d. the 2 substances remained separate
What is new substances were created
a process that changes substances into new substances
what is chemical reaction
How many atoms are in the compound Al2(SO4)?
What is 7
The idea that matter is neither created nor destroyed
What is the law of conservation of mass
A student measures the mass of a candle before and after burning it and found the mass to be lower after burning than before.
This is possible because some products were ______, which escaped and were not measured.
What is gases
True or false?
Iron rusting is an example of a chemical reaction
What is true
a type of chemical reaction which absorbs heat energy
What is endothermic
How many atoms are in the compound Cr2(C2O4)3
What is 20
During a lab experiment, a scientist numbers 3 beakers then pours 150 mL of liquid into each beaker. Each liquid is different. Then, the scientist adds 5g of white solid baking soda to each beaker and stirs. In beaker 1, the baking soda dissolved completely. In beaker 2, the baking soda did not react. In beaker 3, the baking soda bubbled.
In which beaker did a chemical reaction occur?
What is beaker 3
When 2 clear liquids were combined in a beaker, the temperature increased and a yellow powder formed. This most like means that:
What is a chemical reaction took place
We know a chemical reaction has occurred by
What are a change in properties or energy or the production of a precipitate or a gas
What is law of conservation of mass
How many atoms are in the compound 3Cu(NO3)2?
What is 27
A balanced chemical equation is one in which the number of atoms are
What is the same in both the reactants and the products
What is a chemical reaction.
True or false?
Photosynthesis is an example of a chemical reaction.
What is true.