Science Flashcards
Where are alkali metals located on the periodic table?
Group 1, excluding Hydrogen.
What are the properties of alkaline earth metals?
Moderately reactive, 2 valence electrons, good conductors of electricity.
Where are halogens found on the periodic table?
Group 17
Group =
Column
What are the characteristics of noble gases?
Least reactive, full outer electron shell, nonmetals, gaseous at room temperature.
Where are metals, nonmetals, and metalloids located on the periodic table?
*Metals: Left and center of the periodic table.
*Nonmetals: Right side of the periodic table.
*Metalloids: Along the staircase line (Boron to Astatine).
How can you find the number of protons in an atom?
The number of protons equals the atomic number.
How do you calculate the number of neutrons in an atom?
Neutrons = Atomic mass - Atomic number.
When finding the number of neutrons what do you need to do for the mass.
ROUND up or down!!!
How many valence electrons does Oxygen have?
6 valence electrons.
How many orbitals does Sodium (Na) have in its Bohr model?
3 orbitals (1st shell: 2 electrons, 2nd shell: 8 electrons, 3rd shell: 1 electron).
What are the three main parts of an atom and where are they located?
*Protons: In the nucleus.
*Neutrons: In the nucleus.
*Electrons: In orbitals around the nucleus.
Balance the equation: Na + Cl₂ → NaCl
2Na + Cl₂ → 2NaCl.
Balance the equation: Fe₂O₃ + C → Fe + CO₂
Fe₂O₃ + 3C → 2Fe + 3CO₂.
Define and give an example of an element.
*Definition: A pure substance made of only one type of atom.
*Example: Oxygen (O).
Define and give an example of a compound.
*Definition: A substance made of two or more different elements chemically combined.
*Example: Water (H₂O).
Define and give an example of a heterogeneous mixture.
*Definition: A mixture where the components are not evenly distributed.
*Example: Salad
Define and give an example of a homogeneous mixture.
*Definition: A mixture where the components are evenly distributed.
*Example: Saltwater.
What type of reaction is C + O₂ → CO₂?
Combustion reaction.
What type of reaction is Zn + CuCl₂ → ZnCl₂ + Cu?
Single replacement reaction.
What type of reaction is NaCl → Cl + Na?
Decomposition reaction.
What type of reaction is MgO + CaS → MgS + CaO?
Double replacement reaction
What are the characteristics of all chemical reactions?
A chemical reaction needs 2 or more ions, atoms, compounds, or molecules. They can break or create bonds between atoms.
Why does temperature affect how fast a chemical reaction occurs? (Use kinetic energy in your answer.)
When the temperature is raised, kinetic energy increases, causing the bonds to move more quickly. There is a higher chance of the bonds colliding.
What is stored in chemical bonds?
Energy is stored in chemical bonds.
What is wrong with the equation:
H2 + O2 —> 2HO
It is unbalanced; oxygen atoms are not conserved.
What is the balanced version of
H2 + O2 —> 2HO
2H2 + O2 ––> 2H2O
Why do certain chemical reactions require a catalyst?
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.
How do people gain energy to live and survive? Where does that energy come from specifically?
People obtain energy from the environment by drinking/eating resources provided by the earth.
How does pressure affect the rate of a reaction?
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.
Why does adding more or less of a substance change the rate the reaction occurs?
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.
What is the difference between a compound and a molecule?
*A compound is 2 or more different chemically bonded atoms.
- A molecule is 2 or more chemically bonded atoms that are the same.
5 types of reactions are….
*Synthesis reactions
*Decomposition reactions
*Single displacement reactions
*Double displacement reactions
*Combustion reactions
What is an example of synthesis reaction?
C + O2→ CO2
General: A + B → AB
What is an example of a single displacement reaction?
Zn + CuCl2 → ZnCl2+ Cu
General: AB + C → AC + B
What is an example of a decomposition reaction?
NaCl → Cl + Na
General: AB → A + B
What is an example of a double displacement reaction?
MgO + CaS → MgS + CaO
General: AB + CD → AD + CB
What is an combustion reaction?
*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)
