Science

Question 1

Where are alkali metals located on the periodic table?

Answer 1

Group 1, excluding Hydrogen.

Question 2

What are the properties of alkaline earth metals?

Answer 2

Moderately reactive, 2 valence electrons, good conductors of electricity.

Question 3

Where are halogens found on the periodic table?

Answer 3

Group 17

Question 4

Group =

Answer 4

Column

Question 5

What are the characteristics of noble gases?

Answer 5

Least reactive, full outer electron shell, nonmetals, gaseous at room temperature.

Question 6

Where are metals, nonmetals, and metalloids located on the periodic table?

Answer 6

*Metals: Left and center of the periodic table.

*Nonmetals: Right side of the periodic table.

*Metalloids: Along the staircase line (Boron to Astatine).

Question 7

How can you find the number of protons in an atom?

Answer 7

The number of protons equals the atomic number.

Question 8

How do you calculate the number of neutrons in an atom?

Answer 8

Neutrons = Atomic mass - Atomic number.

Question 9

When finding the number of neutrons what do you need to do for the mass.

Answer 9

ROUND up or down!!!

Question 10

How many valence electrons does Oxygen have?

Answer 10

6 valence electrons.

Question 11

How many orbitals does Sodium (Na) have in its Bohr model?

Answer 11

3 orbitals (1st shell: 2 electrons, 2nd shell: 8 electrons, 3rd shell: 1 electron).

Question 12

What are the three main parts of an atom and where are they located?

Answer 12

*Protons: In the nucleus.

*Neutrons: In the nucleus.

*Electrons: In orbitals around the nucleus.

Question 13

Balance the equation: Na + Cl₂ → NaCl

Answer 13

2Na + Cl₂ → 2NaCl.

Question 14

Balance the equation: Fe₂O₃ + C → Fe + CO₂

Answer 14

Fe₂O₃ + 3C → 2Fe + 3CO₂.

Question 15

Define and give an example of an element.

Answer 15

*Definition: A pure substance made of only one type of atom.

*Example: Oxygen (O).

Question 16

Define and give an example of a compound.

Answer 16

*Definition: A substance made of two or more different elements chemically combined.

*Example: Water (H₂O).

Question 17

Define and give an example of a heterogeneous mixture.

Answer 17

*Definition: A mixture where the components are not evenly distributed.

*Example: Salad

Question 18

Define and give an example of a homogeneous mixture.

Answer 18

*Definition: A mixture where the components are evenly distributed.

*Example: Saltwater.

Question 19

What type of reaction is C + O₂ → CO₂?

Answer 19

Combustion reaction.

Question 20

What type of reaction is Zn + CuCl₂ → ZnCl₂ + Cu?

Answer 20

Single replacement reaction.

Question 21

What type of reaction is NaCl → Cl + Na?

Answer 21

Decomposition reaction.

Question 22

What type of reaction is MgO + CaS → MgS + CaO?

Answer 22

Double replacement reaction

Question 23

What are the characteristics of all chemical reactions?

Answer 23

A chemical reaction needs 2 or more ions, atoms, compounds, or molecules. They can break or create bonds between atoms.

Question 24

Why does temperature affect how fast a chemical reaction occurs? (Use kinetic energy in your answer.)

Answer 24

When the temperature is raised, kinetic energy increases, causing the bonds to move more quickly. There is a higher chance of the bonds colliding.

Question 25

What is stored in chemical bonds?

Answer 25

Energy is stored in chemical bonds.

Question 26

What is wrong with the equation:
H2 + O2 —> 2HO

Answer 26

It is unbalanced; oxygen atoms are not conserved.

Question 27

What is the balanced version of
H2 + O2 —> 2HO

Answer 27

2H2 + O2 ––> 2H2O

Question 28

Why do certain chemical reactions require a catalyst?

Answer 28

A catalyst is required for certain chemical reactions because some need energy for the reaction to happen. Without that energy, the reaction is not as likely to happen, or it happens very slowly.

Question 29

How do people gain energy to live and survive? Where does that energy come from specifically?

Answer 29

People obtain energy from the environment by drinking/eating resources provided by the earth.

Question 30

How does pressure affect the rate of a reaction?

Answer 30

Pressure increases the rate of collisions; causing more chemical bonds. When the pressure increases, there is less space for the molecules to move> increasing the density. This provides a higher collision rate.

Question 31

Why does adding more or less of a substance change the rate the reaction occurs?

Answer 31

Adding more or less of a substance changes the rate that which the reaction occurs because there are more collisions, leading to more chemical bonds.

Question 32

What is the difference between a compound and a molecule?

Answer 32

*A compound is 2 or more different chemically bonded atoms.

• A molecule is 2 or more chemically bonded atoms that are the same.

Question 33

5 types of reactions are….

Answer 33

*Synthesis reactions
*Decomposition reactions
*Single displacement reactions
*Double displacement reactions
*Combustion reactions

Question 34

What is an example of synthesis reaction?

Answer 34

C + O2→ CO2

General: A + B → AB

Question 35

What is an example of a single displacement reaction?

Answer 35

Zn + CuCl2 → ZnCl2+ Cu

General: AB + C → AC + B

Question 36

What is an example of a decomposition reaction?

Answer 36

NaCl → Cl + Na

General: AB → A + B

Question 37

What is an example of a double displacement reaction?

Answer 37

MgO + CaS → MgS + CaO

General: AB + CD → AD + CB

Question 38

What is an combustion reaction?

Answer 38

*Combustion reactions - a hydrocarbon reacts with oxygen gas.

*This is also called burning!!!

*In order to burn something you need the 3 things in the “fire triangle”:

*The 3 things:

1) Fuel (hydrocarbon)
2) Oxygen
3) Something to ignite the reaction (spark)