Although all gases closely follow the ideal gas law PV = nRT under appropriate conditions, each gas is also a unique chemical substance consisting of molecular units that have definite masses. In this lesson we will see how these molecular masses affect the properties of gases that conform to the ideal gas law.
The average mass of the pennies in the sample is 2.16 g.
We have a set of pennies from which 10.00% have an average mass of 2.15 g and 90.00% have an average mass of 2.156 g. The average mass (am) of the whole set is a weighted average, that considers the mass (m) and the percentage (perc) of each group. We can calculate it using the following expression.

The average mass of the pennies in the sample is 2.16 g.
You can learn more about weighted average here: brainly.com/question/18554478
Answer:
B. Infrared.
Explanation:
Referring to the electromagnetic spectrum, ultraviolet rays can be measured with a frequency of 10‐⁸, infrared has a frequency of 10‐⁵, visible radiation has a frequency of 0.5 x 10‐⁶ meanwhile X-rays show a frequency of 10‐¹⁰.
Hence, the largest magnitude among the rest goes to infrared rays, which makes B the correct answer.
Answer:
c
Explanation:
that's the direction the truck is moving