Atomic Models, Lewis Dot
The atomic model in which subatomic particles and electron shells are clearly shown is called the ______ model.
Bohr
How many electrons to atoms prefer to have in their outermost electron shell?
8
Describe how the movement of particles changes as a substances changes state from a solid to a liquid. What is gained?
The particles are vibrating in the solid but cannot move past one another, while in the liquid phase, the particles are still attracted to one another but can move past other particles. Energy is gained.
What is the different between speed and velocity?
Velocity is a vector, so it also includes direction, but speed is only a scalar quantity (involves a number only)
What is 1 Newton equivalent to?
1 kg-m/s2
A Lewis Dot structure is made up of an element's ______ _______, surround by its ________ _________ (must get all 4 words to be awarded points).
chemical symbol, valence electrons
Describe where on the periodic table the non-metals are located.
Top right side of the periodic table - the area is shaped like a triangle, and there is a diagonal line between the metals and nonmetals section of the table.
What is radioactivity?
The spontaneous decay of atomic nuclei due to an imbalance in the number of protons and neutrons; radiation is released
Why might one also call the brakes on a car an "accelerator" of sorts?
Acceleration means a change in speed or velocity over time. Whey you slow down the car, you are changing its speed and therefore its acceleration as well.
What is the equation for calculating weight gravity? What are the units of weight?
Force (weight) = m x g (where g is acceleration due to gravity)
A line between the Lewis Dot structures of two atoms that are covalently bonded represents what?
A pair of shared electrons
What do the coefficients and subscripts in a chemical equation show?
The coeffients tell us how many of each molecule there are in the equation. The subscripts show us how many atoms of a particular element there are in a molecule
When a pot of water is boiling, is the temperature of the water changing? Why or why not?
No, because once water is changing state, the energy is being used to overcome the attractions between the particles (so that they fly off into the air as water vapor) rather than increase the temperature of the water.
What does the slope of a distance versus time graph tell us? What would be the standard metric units of the slope of a distance-time graph?
Speed and velocity (traveling forwards or backwards); meters/sec
What does Newton's First Law of Motion say?
This is the law of inertia - every object at rest tends to remain at rest unless acted on by an unbalanced force; every object in motion will tend to stay in motion unless acted on by an unbalanced force.
How would you draw a Lewis Dot Structure for the compound, Lithium Fluoride? (LiF)
See slide answer.
How would you balance the equation on the slide?
Coefficients: 4, 3, 2
What are the three different types of variables in a scientific experiment? Provide the definition for each of the types of variables.
Independent: this is the variable you change in an experiment
Dependent: this is the variable that is being tested in response to the independent variable
Controlled variables (AKA: constants): these are the variables you keep constant during the experiment in order to isolate the effect of the independent variable.
Look at the distance-time graph on the slide. During which time interval was the traveling object stationary? How can you tell?
4-20 sections; flat line (no distance covered)
Names 2 types of non-contact forces.
Gravity, magnetism
How would you draw a Lewis Dot structure for the compound, carbon dioxide? CO2
See answer slide
How would you draw a Lewis Dot Structure for the equation on the slide? Write your answer on a sheet of scrap paper and Ms. de Moor will check it.
See slide for answer.
In clouds, what determines whether or not deposition or condensation is taking place within them?
The altitude (and resulting temperature) of the clouds
What is the overall velocity of the object from 0 to 32 seconds?
Overall displacement = 8 meters
Total time: 32 seconds
Velocity = displacement/time
= 8m/32secs
= -0.25m/sec
What is the value of the acceleration due to Earth's gravity? Would this number be greater or less on the surface of Mars, and why?
9.8m/s2; lower because Mars has far less mass than Earth