17 questions
What happens in a chemical reaction?
Bonds between atoms break and/or are formed
New atoms are created and/or removed
Protons move from one atom to another
Electrons change into protons
How are chemical bonds formed?
Atoms duplicate themselves
Electrons move from one atom to another
The number of protons and electrons in an element is changed
Through changes in an atom's nucleus
Which of the following would indicate that a chemical reaction has occurred?
A new element has been created
A different substance has formed
The total mass has either increased OR decreased
The total number of elements has either increased OR decreased
These are all models of the same molecule. What would this molecule look like in a chemical/molecular formula?
CH
C4H
CH4
4CH
Which would indicate a chemical equation is balanced?
If the number of atoms in the reactants is the same as the number of atoms in the products
If the atoms have ionic OR covalent bonds
If the atoms have full valence shells
If the total energy has remained the same
BEFORE the equation is balanced, how many Hydrogen atoms are present on the reactant side?
6
2
12
8
Why does the number of Carbon atoms need to be the same on both sides of the reaction?
In a chemical reaction, no new atoms can be made
Because the number of Oxygen atoms must be balanced with the number of Carbon and Hydrogen atoms
Because the coefficients and the subscripts need to be equal
It does NOT need to be the same
What coefficient should go in the last blank space in order for the equation to be balanced?
1
2
3
4
How many sulfur atoms are present in this molecule?
4
3
12
1
In the molecule below, which of the following choices is a subscript? (Select all that apply)
3
2
4
SO
What does the Law of Conservation of Mass state?
No new substances can be made or destroyed
No new compounds can be made or destroyed
No new atoms can be made or destroyed
Mass cannot be lost from a physical reaction
Which of the following follows the Law of Conservation of Mass?
CH₄ + 2 O₂ → 2CO₂ + 2 H₂O
2 CH₄ + 2 O₂ → CO₂ + 4 H₂O
CH₄ + 2 O₂ → CO₂ + 2 H₂O
All the above
In a chemical reaction, ________________________ are changed into _______________________.
Reactants; Products
Electrons; Molecules/Compounds
Coefficients; Subscripts
Original Elements; New Elements
Bacteria in milk causes it to curdle over time. What type of change is this?
Chemical
Physical
Both
Neither
Which type of reaction pulls in thermal energy from the environment around it?
Endothermic
Exothermic
When building a HEATING pack, what type of reaction is it?
Exothermic
Endothermic
Moo like a cow for 2 seconds.
Did it!
No Way!