Chemical Reactions
In a chemical reaction the substances to the right of the arrow are called this/these?
What is/are products?
What are the parts of a chemical reaction?
Reactants and products
A substance that enters a chemical reaction is called this.
a reactant
When balancing an equation, these numbers can be changed.
a coefficent
What is it called when both sides of a chemical equation have equal numbers of each element?
Balanced
hydrogen + oxygen → water
Where are the reactants and products in this chemical reaction?
Reactants: hydrogen and oxygen
Products: Water
In the formula 5CaSO4,how many oxygen atoms do we have?
20
How many Aluminum atoms do we have in the products?
Al + O2 → Al2O3
2
True or false: In a chemical reaction, existing substances combine to form new substances.
True
What is it called when both sides of a chemical equation do not have equal numbers of each element?
unbalanced
How many Carbons are there in NaHCO₃?
1
What do we call this:
A + B → AB?
A chemical reaction
Is this a balanced or not balanced equation?
H2S + NaCl → HCl + Na2S
Not balanced
Atoms are made up of smaller particles called subatomic particles. Which is a subatomic particles that has no charge:
Neutrons
Atoms are made up of smaller particles called subatomic particles, name them (3).
electron, neutron and proton
When balancing an equation, these numbers can not be changed.
subscript
NaCl is the formuala for what common compound
table salt
What does an atom of the element with atomic number 6 always have?
6 protons
Two liquids are mixed together. Which of the following does NOT identify the formation of a new substance?
A) gas is produced, B) one liquid dissolves into the other, C) the temperature changes, D) a solid is formed.
one liquid dissolves into the other
Is this equaction a balanced or not balanced chemical equation?
P4 + O2 → P4O6
Not balanced
How many oxygen are in 2C6H8O7
14
In the formula 5CaSO4, what is the 5 and the 4 and what do they represent?
5 - coefficient, indicates how many molecules of that substance are present or used
4 - a small number written below and to the right of an element's symbol that indicates the number of atoms of that element in a molecule or compound
All of the following are examples of chemical change except:
Increase in temperature, release of light, formation of a solid, melting of ice
melting of ice
During a science class investigation, a teacher places a small amount of sugar in a beaker and heats it over a candle. Which of the following would be the best evidence that a change in the chemical properties of the sugar has taken place?
A) The sugar gets hotter. B) The sugar gets larger. C) The sugar turns into a liquid. D) The sugar turns black.The sugar turns black.
When vinegar and baking soda are combined, bubbles and foam are produced.
What evidence demonstrates that a chemical change has occurred?
A) A color change occurs. B) A gas is formed. C) A solid is dissolved. D) A precipitate is formed.
A gas is formed.