Honors Chemistry. 1) Explain how you can take the mass of a substance, such as salt on the...

Warm-ups

Honors Chemistry

8/17/15

• 1) Explain how you can take the mass of a substance, such as salt on the electronic balance without pouring the salt directly on the balance. (Be specific in your answer).

8/18/15• 1) You complete a lab on the boiling point

of water. You do 3 trials and get the boiling point to be 99.80⁰C, 99.90⁰C, and 100.00⁰C. The actual boiling point of water is 100.00⁰C. Is your data accurate, precise, both, or neither?

• 2) Seeing Madison shoot 10 shots is an example of which type of measurement.

• An experiment is being completed to determine which type of light bulb will burn the longest.

• 3) Determine the independent variable in the experiment.

• 4) Give an example of an inference.

8/19/15• 1) Compare and contrast between

scientific theory and scientific law.• 2) Harley and Halle do an

experiment to determine the melting point of a substance. They do the lab and get results of 2.00, 2.10, 2.25, 2.30, 2.36, and 5.00 degrees Celsius. The actual melting point of the substance is 0.00 degrees Celsius. Are their results precise, accurate, both, or neither?

8/20/15• Which brand of razor works the best?• Research is completed to see which brand

of razor gives the closest shave. Three groups are chosen. Each group has the same number of men, same race of men, same type of facial hair, uses the same type of shaving cream, and uses the same method of shaving. One group of men do not shave.• 1) Determine what the dependent

variable in the research is.• 2) What is the independent variable?• 3) Name the control for the research.

8/21/15

• 1) How many days do you have to prepare for the end of the world if NASA makes an announcement that an Asteroid is going to hit the Earth in 7,500.00 minutes?

8/24/15

• 1) A high school basketball court is 2560.00 cm from baseline to baseline. How many times would you need to run down the court to travel a total of 2.00 miles during practice?

8/25/15

• 1) Determine the temperature (in Fahrenheit) in this room if you are told it is 293.00 K.• 2) The freezing point of Mercury is -38.83 ºC. During an experiment, Michael and Jonah find the freezing point of the element to be -40.00 ºC. What is the percent error of their experiment?

8/26/15

• 1) We are going to place 21 boxes from the floor to the ceiling. Each box measures to be 145.14 mm. What is the height in feet of the room from the floor to the ceiling?

8/27/15

• 1)

8/31/15

• 1) The height of a basketball is 260.35 mm. We build a new rack to put the basketballs in that is 3.40 feet high. How many basketballs can fit in one rack?

9/1/15• Using the Handout covering Scientific Notation and Scientific Figures, complete the following.• 1) Complete Numbers 1, 2, 3, 7, 8• 2) Determine the answers for 4 and 9 (Do the math)

9/2/15• 1) How many mm are in 3.57x10-

5 km?• 2) During an experiment, we find the mass of a piece of copper to be 156.1 grams and the volume of copper to be 17.5. Determine the density of copper. (Density= mass/volume).•Make sure you put the answer with the correct number of significant figures.

9/3/15• 1) Determine the mass of an object that has a volume of 250 mL and a density of 19.31 g/mL.• Just multiply the numbers.•Make sure you put the answer with the correct number of significant figures.

• 2) Describe an atom in your own words.

9/4/15• 1) How do you determine the identity of an element?• 2) Determine the volume of a substance given the density of the substance is 8.92 and the mass is 2.3x103 g.• To find volume: mass/density

•Make sure you put the answer with the correct number of significant figures.

9/8/15• 1) Which subatomic particle has a mass of 0 and is found outside the nucleus?• 2) Why can’t the number of protons of an element ever change?• 3) What is one of the findings that Dalton stated in his Atomic Theory that is still proven correct today?

9/9/15• 1) An element of Magnesium loses 1

electron and it has a mass number of 25 and 13 neutrons. Determine the charge of Magnesium.

• 2) What changes in an atom of an element to make it become charged?

• 3) If an element has a mass number of 39, 20 protons, and a charge of 2.•How many neutrons does the element have?•Determine the electrons the element has?•Name the element.

• 4) Which subatomic particle has a mass of 1 and a charge of 0?

9/10/15• 1) If a neutral atom gains 3 neutrons and loses

3 electrons, is the atom neutral, positive, or negative?

• 2) An atom of Carbon has 6 protons, 7 neutrons, and 4 electrons.• What is the mass number of Carbon?• Determine the charge on Carbon.• If it has a charge, what is this charged particle called?

• 3) The following 2 atoms represent ____________________.• N-14• N-15

• 4) Which of the following changes in the isotopes of an element?• (Mass Number, Atomic Number, Neutrons, Protons)

9/11/15•1) List at many relevant, distinct facts as you can about the following isotope of Phosphorus.

30

15 P-3

9/14/15• 1) Determine the

charge of the atom if one of the electrons were removed. What is the name of the element?• 2) An unknown

element has two isotopes with atomic masses and percent abundances of 6.00 (7.50%) and 7.00 (92.50%). What is the name of the element?

9/16/15

Element Atomic Number

Mass Number

Protons Electrons

Neutrons

Charge

Cesium 134 +1

Thorium 90 143

Selenium

79 36

9/16/15• 2) An unknown element has a mass number of 8, a charge of positive 1, 2 electrons, and 5 neutrons. What is the name of the element?• 3) K-38 represents a/an ________________.• 4) Explain why the atomic number of an element is important.

9/18/15•1)