Transcript Lab Safety and Introduction to Chemistry

Chemistry
• 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).
• 1) J.J. is found to be 6’4” is an example of which type of
measurement.
• 2) Give an example of an inference.
• An experiment is being completed to determine which
type of light bulb will burn the longest.
• 3) Determine the dependent variable in the experiment.
• Use the following information to answer questions 1-4.
• Which type of sod grows the best in Georgia weather? A
study is completed to determine the above question.
Three types of sod is studied over a course of 2 years.
The type of soil used is the same, the same type of lawn
care is completed, and they are all in the same type of
environment. One lawn was left with only dirt for the
yard for the 2 year period.
• 1) Determine the independent variable.
• 2) What is the dependent variable?
• 3) What is the control in the experiment?
• 1) We do a lab on a substance that has a boiling point of
123.00 ˚C. We completed four trials on the boiling point of
the substance and got results of 119.00 ˚C, 119.50 ˚C,
119.80 ˚C, and 120.05 ˚C. Are our results precise, accurate,
both, or neither?
• 2) Explain how a scientific theory and scientific law are
different.
• 3) How should acid and water be mixed together?
• Morgan and Kayla want to find out which brand of
women’s deodorant is the most effective when working
out. They have 4 groups set up for the experiment. All
of the groups complete the same workout, have the
same number of women in each group, and workout for
the same length of time. Group 1 uses Secret, Group 2
uses no deodorant, Group 3 uses Dove, and Group 4
uses Lady Speed Stick.
• 1) What is the control.
• 2) Name a constant.
• 3) What is the independent variable?
• 4) What is the dependent variable?
• Research is completed to see which type of battery lasts
the longest. Five different brands of batteries are tested.
The batteries were used in the same type of objects
(toys, flashlights, razors, etc.), and used the same
duration of time.
• 1) What is the independent variable?
• 2) Explain how you would solve the number of meters
in a 1.60 km race.
• 1) A cell found in the human body is found to have a
diameter of 50.00 um. What is the diameter of the cell
in m.
• 2) The track at school is 0.40 kilometers long.
Determine the length of the track in miles.
• 1) How many cups of Kool-Aid are in
21,290.40 mL?
• 2) Determine the number of km it is to
Hiram (Hiram is 20.00 miles from
Rockmart).
• 1) We look up the density of copper on the Internet
and find the density to be 8.92 g/mL. During a lab,
Evan and Jay find the density of a piece of copper to
be 6.35 g/mL. Determine the percentage error of their
findings.
• 1) An object is found to have a melting point of -15.83
ºC during an activity. Determine the percentage error of
the measurement if the textbook had the object’s melting
point to be -12.04 ºC.
• 2) A steak is 1021.50 grams. How many ounces is the
steak?
• 3) Determine the temperature in Celsius of a
microorganism that has a temperature of 260.37 Kelvin.
• 1) In a lab, we take the temperature of salt water. We
find the temperature of the water to be 43.00 ºC. What
is the temperature of the water in Fahrenheit?
• Use the following scenario to answer questions 2-3.
• Tyler wants to know which kicking position produces
the most power when kicking field goals.
• 2) What is the dependent variable?
• 3) Determine the independent variable.
• 1) In a lab, McKayla and Johnna find the atomic mass
of potassium to be 30.00, 38.00, and 38.25. The atomic
mass of potassium found in the book is 39.10. Are
McKayla and Johnna precise, accurate, both or neither?
• 2) The average atomic mass for McKayla and Johnna is
35.42. What is the percentage error of the measurement
if the actual atomic mass is 39.10?
• 3) The football field is 120.00 yards in length.
Determine the length of the field in miles.
• 1) Determine the number of mm in 0.058 km.
• 2) How many kilometers are in 4,628.50 feet?
• 3) An experiment is completed to see which brand of
running shoe lasts the longest when exercising. What is
the independent variable?
• 1) Which subatomic particle has a relative
mass of 0?
•(Proton, Neutron, Electron)
• 2) Explain how you can determine an
element’s atomic number.
• 3) How many L are in 50 mL?
• A study is completed to find out which grade
(87, 89, 93) of gasoline allows a car to perform
most effectively over time. Miles driven in the
cars, environmental conditions, how the cars
were driven, and maintenance of the cars all
remained the same.
• 1) Determine the independent variable in the
study.
• 2) What is the dependent variable?
• 3) Name a constant.
• 4) How many meters are in 756,850 mm?
• 1) Which area (nucleus or electron cloud)
encompasses the largest volume of an
atom?
• 2) Which subatomic particle is the least
massive?
• 3) Why can’t the number of protons of an
element ever change?
• 4) Give an example of a qualitative
measurement.
• 1) If Iodine has an atomic number of 53 and
72 neutrons. Determine the mass number of
Iodine.
• 2) Find the number of neutrons an atom of
Rhodium has if it has a mass number of 104.
• 3) Iridium has 114 neutrons and a charge of 2.
•What is the element’s mass number?
•How many electrons does the element have?
• 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.
• 1) List as many relevant, distinct facts
as you can about the following isotope.
86
•38
2
Sr
• 1) What is the
mass number 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?
• 1) If a neutral atom gains 3 neutrons and
loses 3 electrons, is the atom neutral, positive,
or negative?
• 2) The following 2 atoms represent
____________________.
•N-14
•N-15
• 3) Which of the following changes in the
isotopes of an element?
•(Mass Number, Atomic Number, Neutrons,
Protons)
• 1) An unknown element has 3 stable isotopes
with atomic masses and percent abundances of
the following: 1) 16.00 and 99.759%, 2)
17.00 and 0.037%, 3) 18.00 and 0.204%.
Determine the average atomic mass of the
element and name the element.
• 2) Three isotopes of Sodium are Na-22, Na-23,
and Na-24. Which isotope of Sodium is the
most abundant in nature? Why?
• 1) An atom of Carbon has 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? (Cation or Anion)
• 2) Which subatomic particle has a mass of 1 and a
charge of 0?
• 3) Where is most of the volume found in an atom?
(Nucleus, outside the atom, electron cloud)
• For the following 5 questions, state whether each
characteristic is ionic or covalent.
• 1) Shares electrons
• 2) Occurs between metals and nonmetals
• 3) Normally soluble in water, but not nonpolar
liquids
• 4) Will not conduct an electrical current
• 5) High Melting Point
• 6) Compare and contrast the following:
• Ca-39 and Ca-40
• 7) Where are the metals located on the periodic
table?
• 1) An ion of an element has 62
neutrons, 46 electrons, and a charge of
2. Determine the identity of the
element.
• 2) How are ionic and covalent
compounds different?
• 1) How are ionic bonds formed? (Make
sure you discuss how the electrons move)
• 2) How does an atom become as stable as
possible?
• 3) The force that holds 2 atoms together is
called ______________.
• 4) How are covalent bonds formed?
• 5) Draw an example of a covalent bond.
• 1) Draw the electron dot structure for Helium.
• 2) What group or family contains elements with 5 valence
electrons?
• 3) Which group/groups of elements is/are the most
similar?
• A)
• B)
• C)
• D)
Helium and Magnesium
Fluorine and Iodine
Hydrogen and Helium
Carbon and Aluminum
• Se-78 has a charge of -2. Answer the following questions
using this information.
• 4) How many electrons does the atom have?
• 5) Determine the number of neutrons.
• 6) Se-78 represents a/an ______________________.
• 1) Which subatomic particle is involved in
the bonding of atoms? (Proton, Electron,
Neutron)
• 2) Write the chemical formula for Aluminum
Phosphide.
• 3) We are going to combine Magnesium
and Neon. What is the formula for this
compound?
• 4) Determine the name for the following
chemical formula:
•Ca3N2
• Classify the following compound as ionic or
covalent.
• 1) C3H8
• 2) When writing ionic compounds, which
should always being written first:
• (Metal or Nonmetal)
• 3) Write the name for the following compound:
• SrCl2
• 4) Determine the chemical formula for the compound
that forms when oxygen reacts with aluminum.