Vocabulary
The smallest basic unit of matter
Atoms
In water how many Hydrogen atoms are there?
2
During a chemical reaction atoms can not be ________ nor __________.
created, destroyed
What are three states of matter?
solid, liquid, gas
A substance has a unique color, density, and solubility. What are these called?
Properties
Also known as outputs of a chemical equation
Products
In Carbon Dioxide, how many Oxygen atoms are there?
2
What happens to molecules during a chemical reaction.
They break apart, rearrange and recombine.
What do properties help us do?
identify a substance.
A student wants to identify an unknown substance. Which would be the best way to determine if it is the same as a known substance?
Test/Compare several properties.
What is a molecule?
A group of 2 or more atoms together
What is H2 (little 2) considered?
Molecule
Can one chemical reaction produce more than one product?
Yes
What is another property you can test to find out a substance other than color and density?
Flammability, boiling point, solubility, scent, texture
An unknown substance has a density of 2.71 g/cm³. Calcium nitrate has a density of 2.50 g/cm³, and calcium sulfate has a density of 2.32 g/cm³. What does this suggest?
The unknown is a new substance.
What are the inputs of a chemical reaction also called?
Reactants
How many atoms of each element are in C₆H₈O₇?
6 Carbon, 8 Hydrogen and 7 Oxygen
A student mixes two substances and observes that a new substance forms. What process may have occurred?
A chemical reaction
What happens to total mass in a closed system during a chemical reaction?
Stays the same
A student mixes two substances in an open container. After a chemical reaction, the measured mass decreases. The student claims that atoms were destroyed during the reaction. Is the student correct?
No, matter cannot be destroyed it was in an open system and gas escaped.
What is a chemical reaction?
the way that atoms can be rearranged to make new substances
How many atoms are in Ca(HO)4 (little 4)
9
A reaction starts with 12 atoms in total. How many atoms should be present in the products if all matter is accounted for?
12 atoms
Three liquids are poured into the same container. Liquid A is less dense than Liquid B but liquid C is more dense than liquid B. If the liquids do not mix, where will each liquid settle, and why?
Liquid A will settle on top, Liquid B will settle in the middle, and Liquid C will settle at the bottom
More dense things sink. Less dense float.
A student claims that a chemical reaction produced 10 oxygen atoms, but the reactants contained only 6 oxygen atoms. Is the student's claim possible? Explain your reasoning.
No. Atoms cannot be created or destroyed during an ordinary chemical reaction, so the products must contain the same total number of oxygen atoms as the reactants.