Chemistry
1. Explore Sodium bicarbonate compound and any questions that you may have about it or its properties that you would like to understand better. In your post, include a link to or a description of the elements that form the compound. Using the web resource https://ptable.com/#Properties, find an interesting feature about the element or elements that sodium bicarbonate is composed of and comment on how you think this might be relevant to the compound.
2. Then answer the questions in the attached document
Chemistry
40. You find an old bathroom scale at a garage sale on your way home from getting a physical exam from your doctor. You step on the scale, and it reads 135 lb. You step off and step back on, and it reads 134 lb. You do this three more times and get readings of 135 lb, 136 lb, and 135 lb.
a. What is the precision of this old bathroom scale? Would you consider this adequate precision for the type of measurement you are making?
b. The much more carefully constructed and better-maintained scale at the doctors office reads 126 lb. Assuming that you are wearing the same clothes that you wore when the doctor weighed you, do you think the accuracy of the old bathroom scale is high or low?
42. If you are given the following values that come directly or indirectly from measurements, what will you assume is the range of possible values that they represent?
a. 2.2 L (the volume of a basketball)
b. 3 m (the diameter of a hair)
c. 2.0 10-6 nm (the diameter of a proton)
d. 1.98 105 kg (the mass of a whale)
36. When a small container of liquid ammonia is opened in a classroom, in a short
time everyone in the room can smell it.
a. Describe the changes that take place when liquid ammonia vaporizes to
form a gas.
b. Why does the gaseous ammonia expand to fill the whole room?
c. Why does the gaseous ammonia occupy a much greater volume than the
liquid ammonia?
38. A drop of food coloring is added to water. With time, it spreads evenly through
the water so that the mixture is all the same color.
a. Describe what is happening to the food coloring and water particles as the
coloring spreads into the water.
b. When a drop of food coloring is added to two bowls of water, one at 20 C
and the other at 30 C, the coloring spreads more quickly in the bowl at
the higher temperature. Why?
49. Write the name of the group or family to which each of the following belongs.
a. strontium c. iodine
b. lithium d. xenon
51. Identify each of the following elements as a solid, a liquid, or a gas at room
temperature and pressure.
a. chlorine d. W
b. Se e. xenon
c. mercury f. As
57. Which element would you expect to conduct electric currents well, aluminum or
iodine? Why?
62. Write definitions of the terms atomic number and mass number. Which of these
can vary without changing the element? Why? Which of these cannot vary
without changing the element? Why?
64. Write the atomic number for each of the following elements.
a. sodium d. Pu
b. As e. iron
c. strontium f. Se
67. Write the name and symbol for the elements that fit the following descriptions.
a. 78 protons in the nucleus of each atom.
b. 42 electrons in each uncharged atom.
c. 80 electrons in each +3 cation.
d. 18 electrons in each 2 anion.
69. Write definitions for the terms atom and molecule and use them to explain the
difference between hydrogen atoms and hydrogen molecules.
