Atoms and Molecules
Name the parts of an atom, their charges, and their location.
Protons - Positive (nucleus) Neutrons - Neutral (nucleus) Electrons - Negative (electron shell/orbital)
What is the difference between a compound and a mixture?
Compounds are held together by forces called chemical bond and cannot be separated by physical means. Mixtures can be separated by physical means.
What is another name for evaporation? Is it a physical or chemical change?
Vaporization; Physical because it is just a change in state. No new substance is formed.
Aluminum foil represents a metal. Name at least 2 of its physical properties?
Shiny (luster), malleable, conducts electricity, ductile, etc
What is the difference between an open system and a closed system?
An open system is not contained. The gas particles can escape. A closed system will not allow any gas to escape.
What two particles make up atomic mass? What charge does each carry?
Protons and Neutrons - Positive and Neutral
What is the difference between an element and a compound?
An element is made up of one type of atom while a compound is made up of two or more types of atoms (elements) chemically bonded.
When you add more and more heat to gas particles, what happens?
Ionization: The charged particles in the atom break apart and move freely from one another; they change from gas to plasma
What is the difference between a chemical change and a physical change?
Chemical changes result in the formation of a new substance. Different molecules of compounds will be produced; physical changes can be manipulated to get your original substances back. The same atoms/molecules are present before and after physical changes.
Define the Law of Conservation of Matter.
Matter cannot be created or destroyed.
Name the Element in Group 2, Period 4.
Calcium (Ca)
Write down the two types of mixtures and what they mean.
Homogenous = uniform (looks the same) throughout
Heterogenous = not uniform throughout
Connect the three main states of matter to their descriptions:
indefinite shape, definite volume
definite shape, definite volume
indefinite shape, indefinite volume
indefinite shape, definite volume = liquid
definite shape, definite volume= solid
indefinite shape, indefinite volume = gas
Give at least 2 examples of both a chemical change and a physical change.
Answers Vary
How does a balanced chemical equation represent the Law of Conservation of Matter?
In a balanced chemical equation, there is the same number of atoms of each element in the reactants as there are in the products. This shows the Law of Conservation of Matter, because no mass was gained or lost. We ended up with the same amount of matter that we started with.
Draw an atom on the board with a greater atomic mass than an atom of Helium.
Answers Vary
On your dry erase board, draw a picture of an element, a compound, and a mixture. Explain the differences.
Description: Elements have only one type of atom; Compounds are two or more different types of atoms that are chemically bonded; Mixtures are different types of atoms or molecules that are not chemically bonded. They can be physically separated.
How does Kinetic Theory relate to temperature?
Kinetic Theory tells us about the movement or behavior of particles. Temperature relates, because the more heat you add, the faster particles move. The more heat you remove, the slower particles move.
Pretend you are performing an experiment, mixing two chemicals without adding heat. Suddenly, the container holding the two chemicals gets very hot. Was this a chemical or physical change? Explain your answer.
This would be a chemical change, because the reaction released the heat. We did not add the heat, it was produces by the reactants.
If you add 30g of Element A to 42g of element B, how many grams of matter will be in your final product?
30g + 42g = 72g of product
One atom has 5 protons and 5 neutrons. Another atom has 5 protons and 7 neutrons. What element do both of these atoms represent?
Boron
Salt (NaCl) is a compound. Water (H2O) is a compound. When the two are mixed together, the salt will dissolve in the water. Will they form a compound or a mixture? How do you know and what might you do to try to separate these?
They will form a mixture. Dissolving is a physical change. We could boil the water completely off and still have salt. The substances are not changed, only physically combined.
Describe the movement of particles in liquid water, in ice, and in steam.
In liquid water, particles are close together but able to move past each other. In ice, the particles are very close together and only vibrate in place. In steam, the particles are far apart and moving fast and freely.
Name 5 things you might notice when you see a chemical change occurring.
Bubbling, Color Change, Smoke, New Substance, Precipitate (solid forming in liquid) (answers may vary)
Two groups started an experiment with 20g of antacid tablets, 23g of a ziplock bag, and 50g of water. Group 1 ended up with a final mass of 90g. Group 2 ended up with a final mass of 92.9g. Which group had more accurate results? Explain your reasoning.
The Law of Conservation of Matter tells us we should start and end with the same amount of matter. If both groups started with the same mass of supplies and ingredients (20g+23g+50g=93g), the group with the ending mass closer to 93g would be more accurate, because no matter should be lost or gained. In conclusion, Group 2 had more accurate results.