A substance made of 2 or more different elements linked together.
100
What happened when electricity was passed through water
The water compound was broken down into Hydrogen and Oxygen gas.
100
Name 1 thing you can do to water to make it undergo a physical change.
Change its state/phase
100
Explain why this is a compound:
H2O
Because it is made up of 2 different elements, hydrogen and oxygen. They are chemically combined to form a new substance, water.
100
What is the smallest part of a compound called?
Molecule or Formula unit
200
Explain why heat cannot break down an element.
Elements cannot be broken down by anything because they are made of only one type of atom so they are already in their simplest form.
200
What types and how many of each atom are in C6H12O6?
6 Carbon
12 Hydrogen
6 Oxygen
(As a side note the numbers in the formula above should be a small subscript, however this program does not allow subscripts)
200
What always happens as a result of a chemical change?
A new product is formed. Atoms are rearranged.
200
Describe what products and reactants mean in a chemical equation
Reactants are what you begin with in a chemical reaction they are located on the left side of the equation. Products are what you end up with after a chemical reaction, they are located on the right left side of the equation
200
What is the smallest part of an element called?
Atom
300
What is electrolysis?
The process of breaking down water with electricity.
300
HCl has been added to calcium carbonate. Bubbling occurs. Explain why.
A new substance, carbon dioxide, has formed in this chemical reaction.
300
What are the 3 ways we broke down compounds?
With Heat, Electrical Currents or Acids
300
What does the arrow (----->) mean in a chemical equation?
Yields or produces
300
If 30 grams of Hydrochloric acid react with 20 grams of Zinc. What is the mass of the products after the reaction? Why?
50 grams, the law of conservation of mass/matter states that mass or matter cannot be created or destroyed during a chemical reaction. In other words what you start with is what you end up with, the atoms are simply rearranged.
400
What is the equation for the electrolysis of water
2H2O ---> 2H2 + O2
(As a side note the 2 AFTER the H's and AFTER the O should be a small subscript, however this program does not allow subscripts)
400
Explain why heat is able is break down a compound.
Compounds are made up of bonded atoms, that heat can break apart, which causes the compound to break down into new substances.
400
What is corrosion? What are 2 examples?
The slow wearing away of a metal. Rust and tarnish are examples
400
How many of each atom are in this molecule?
2NaHCO3
2 Na (Sodium)
2 H (Hydrogen)
2 C (Carbon)
6 O (Oxygen)
(As a side note the 3 above should be a small subscript, however this program does not allow subscripts)
400
What type of change is burning sugar? What type is dissolving sugar in water?
Burning=chemical. dissolving = physical
500
Name 4 Indicators of a chemical change
Gas is released, heat is released, light is emitted, color change, precipitate is formed, a new substance is formed
500
Name 4 indicators of a physical change.
Change in size, shape, texture, phase/state
500
Name the products and reactants in the following chemical equation 2H2O ---> 2H2 + O2
(As a side note the 2 AFTER the H's and AFTER the O should be a small subscript, however this program does not allow subscripts)
Reactants are 2H2O. Products are 2H2 + O2
500
If an atom has 5 electrons and 6 neutrons, what is the atomic number and what is the mass number
Atomic number = number of protons = number of electrons = 5. Mass number = protons + neutrons = 11
500
What family/group of elements do not form compounds easily?
Group 18 Nobel gases. They are not reactive so they do not easily form compounds