Science Test
What is a physical change?
A change in the shape or form of matter
What is a chemical change?
A change where matter is rearranged to make a new substance
What is a solution?
A substance that is equally distributed in a container
What is a Closed System?
A system that does not allow matter to be exchanged, but does allow energy (heat) to be exchanged
Number placed in front of a chemical formula
Coefficient
The scientific rule that says that mass is never made and never lost is called _.
Conservation of Matter
The Law of Conservation of Mass says that matter can neither be __________ or __________.
Created; destroyed
The letters in a chemical formula represent what?
Elements
In sweet tea, the sugar can be separated from the solution by _.
Evaporation
How can energy (heat) be given to an Open System (boiling water)?
From the hot stove
How can matter be given to a Closed System (boiling water)?
It can't
How can matter be taken from a Closed System (boiling water)?
It can't
What makes a product unique?
It is a unique combination of molecules
Measure of the amount of matter
Mass
Anything that has mass & takes up space
Matter
How can matter be taken from an Open System (boiling water)?
Matter is leaving the system through steam
Smallest unit of a compound; 2 or more atoms chemically bonded
Molecule
If a nail rusts, will it have more or less mass than the nail before it rusted?
More because the rust has mass
What kind of change are reactants and products for?
Only chemical
What is the change of matter between states called?
Phase change
What changes does Conservation of Matter apply to?
Physical and Chemical
When sodium and chlorine combine to form sodium chloride, sodium chloride is the:
Product
Substances that form as the result of a chemical reaction
Products
What are substances created in a reaction called?
Products
Substances present at the start of a chemical reaction are what?
Reactants
What are the substances that react to form a new substace called?
Reactants
During the evaporation of water, where do the water molecules go?
Released into the air
Number written below & to the right of a chemical symbol
Subscript
How much do products weigh?
Sum of weight of all the reactants
According to the Law of Conservation of Mass, what happens to the wood and oxygen when it is burned?
The atoms in the wood and oxygen rearrange and form smoke and ash.
Jason poured 500 grams of water into a container and tightly sealed it. The water was allowed to freeze. Which is most likely true about the ice that formed?
The mass of the ice is the same as the mass of the water.
How can energy (heat) be taken from a Closed System (boiling water)?
The pan gets hot, even on the outside, so energy is escaping
How can energy (heat) be given to a Closed System (boiling water)?
The pan warms up from the stove, where heat is being given to the pan
What is the Conservation of Mass?
The rule that matter and mass are never made or lost, they just change form, and includes the formulas of products and reactants
What is the Conservation of Matter?
The rule that matter can't be created or disappear, it can only move, rearrange, and change form
How can energy (heat) be taken from an Open System (boiling water)?
The steam is hot, so that is heat leaving
Is this equation balanced or unbalanced? H2 + O2 --> H2O
Unbalanced
A change where a substance changes form or shape
What is a physical change?
How can matter be given to an Open System (boiling water)?
You can pour water into the pot
What is an Open System?
Any system that freely exchanges energy (heat) and matter with the outside world
What is a System?
Anything that exchanges matter and energy (heat)
Each lego in your BLOCK party demonstration represented a what?
Atom
Smallest unit of an element
Atom
How many atoms are in the products below? 4Fe + 3O 2 = 2Fe 2 O 3 4, 3, 2 are coefficient 2, 2, 3 are subscript
10
In a reaction A + B ----> C, reactant A has 5g and product C has 9g. How many grams does reactant B should have?
4g
Anthony is performing an experiment. He adds 0.25 grams of baking soda to 5 grams of water and stirs. Anthony watches as the baking soda dissolves in the water. If Anthony weighs the water and baking soda solution, what will its mass be?
5.25 grams
A 55-gram egg is placed in a pot. After the egg is boiled, which is most likely the mass of the egg?
55 grams
How many oxygen atoms are in the products for the chemical reaction below? 4Fe + 3O 2 = 2Fe 2 O 3 4, 3, 2 are coefficient 2, 2, 3 are subscript
6
