Answer:
i think its 2
Explanation:
because the H2 is seperate from the others it is the only one with a number.
Answer:
To check if it's properly cleaned.
Explanation:
When you finish using a microscope, you have to take out all your samples you were using and make sure it is completely clean so that no further contamination affects future sample analysis.
Also when you begin to use it, make sure it is clean so that when you analyze your sample(s) are free from other unexpected agents.
Solids have least energetic molecules because they are tightly packed.
Answer:
The probability of spinning red with the spinner or rolling an odd number with the die is 
Explanation:
Given that,
Total color in spinner = 4
Let the area of four parts is equal in the spinner.
We need to calculate the probability of spinning red
Using formula of probability

Put the value into the formula

We need to calculate the probability of odd number of the die
Using formula of probability

Put the value into the formula


We need to calculate the probability of spinning red with the spinner or rolling an odd number with the die
Using formula of probability of two events which is independent

Put the value into the formula


Hence, The probability of spinning red with the spinner or rolling an odd number with the die is 
There are several information's already given in the question. Based on those information's, the answer can be easily deduced.
Amount of gasoline required by Harry's car to travel 25 miles = 1 gallon
Then
amount of gasoline required
by Harry's car to travel 15000 miles = 15000/25
= 600 gallons
So
Amount of CO2 released by burning 1 gallon of gasoline = 20 pounds
Then
Amount of CO2 released
by burning 600 gallon of gasoline = 600 * 20
= 12000 pounds
From the above deduction, it can be concluded that the amount of CO2 that will be added by Harry's car to the atmosphere is 12000 pounds.