Work, Power, Machines
How do you know when work is done?
The object moves in the direction of the force applied
What type of chemical reactions has to do with radioactive decay?
Nuclear reactions
Which of the following are chemical properties:
Boiling point
Reactivity
Color
Reactivity
Name 1 way you can increase dissolving rate of a solute.
Increase in temperature or increase in motion (stirring)
Most elements on the periodic table are classified as what?
Metals
Which has more power? When you run up 1 meter of stairs or walk up 1 meter of stairs?
Running up 1 meter of stairs (P = w/
triangle t)
Which of the following is an example of a synthesis reaction?
A) Water boiling into steam
B) Sodium and chlorine forming sodium chloride
C) Ice melting into water
D) Sugar dissolving in water
B) Sodium and chlorine forming sodium chloride
What is matter?
Anything that has mass and takes up space
A student grabs a cup of saltwater. What is the solute and what is the solvent?
Solute: Salt
Solvent: Water
What are the horizontal and vertical rows on the periodic table called?
Horizontal: Periods
Vertical: Groups
A football player tries to shove a player from the opposing team. The player did not move. Was work done?
No. They player must move for work to be done.
Why do we balance chemical equations?
The law of conservation of mass. You need to have the same number of atoms before and after a chemical reaction since they are not created or destroyed.
What is the difference between a homogenous and heterogenous mixture?
Homogenous: parts are evenly combined in the substance
Heterogenous: parts of the substance are separate
What is a saturated solution?
The maximum amount of solute that will dissolve is in the solution. (if you add more the solute such as salt it will not dissolve)
What do periods and groups tell us about an element?
Periods: Energy Levels
Groups: Valence Electrons
What’s the difference between resistance force and effort force?
Resistance Force- the force applied by the machine
Effort Force- the force applied by the person
Balance the following chemical reaction
Al + HCl → AlCl3 + H2
2 Al + 6 HCl → 2 AlCl3 + 3 H2
What's the difference between an element and a compound?
Element: made of 1 type of atom (Oxygen)
Compound: made of 2 or more different types of atoms (CO2)
What is the numerical range acids, bases, and neutral solutions on the pH scale?
Acids:0-6.99 (less than 7)
Bases:14-8 (more than 7)
Neutral: 7
What is the most reactive group on the periodic table called?
Alkali Metals
How do machines make work easier? Name TWO of three ways.
Decreasing Effort Force- the force that YOU must apply
Increasing the distance over which the force is applied
Changing the direction of the applied force
Name the 6 types of chemical reactions we discussed in class.
Synthesis Reaction
Decomposition Reaction
Single Displacement Reaction
Double Displacement Reaction
Combustion Reaction
Acid/Base Reaction
What makes sublimation and deposition unique?
They both skip the liquid phase in their phase change.
Sublimation: Solid to gas (dry ice to CO2)
Deposition: Gas to solid (water vapor to frost)
What do acids and bases each produce when dissolved in water?
Acids: H+ (Hydrogen Ions)
Bases: OH- (Hydroxide Ions)
What makes up atomic numbers? What makes up atomic mass?
Atomic Mass: Protons & Neutrons