Answer:
B. The elements that have similar densities and atomic sizes
Explanation:
Answer:
b) 
The confidence interval for this case is given (6.21, 6.59)
So we can conclude at 95% of confidence that the true mean for the PH concentration is between 6.21 and 6.59 moles per liter
c) Since the confidence interval not contains the value 7 we reject the hypothesis that the true mean is equal to 7. And the same result was obtained with the t test for the true mean.
Explanation:
We assume that part a is test the claim. And we can conduct the following hypothesis test:
Null hypothesis: 
Alternative hypothesis 
The statistic is to check this hypothesi is given by:

We know the following info from the problem:

Replacing we got:

And the p value would be:

Since the p value is very low compared to the significance assumed of 0.05 we have enough evidence to reject the null hypothesis that the true mean is equal to 7 moles/liter
Part b
The confidence interval is given by:

The confidence interval for this case is given (6.21, 6.59)
So we can conclude at 95% of confidence that the true mean for the PH concentration is between 6.21 and 6.59 moles per liter
Part c
Since the confidence interval not contains the value 7 we reject the hypothesis that the true mean is equal to 7. And the same result was obtained with the t test for the true mean.
I believe the answer is b
The answer to your question would be sound because dogs have excellent hearing so when it hears loud thunder it was a frightened reaction
Answer:
96.09 g/mol
Explanation:
You just need to first get the atomic weights of the elements involved. You can easily get these from your periodic table.
If you are going to do this properly, please use the weight with at least two decimal places for accuracy (e.g. 15.99 g/mol).
Also, please take note that I will be using the unit g/mol for all the weights. Thus,
Step 1
N = 14.01 g/mol
H = 1.008 g/mol
O = 16.00 g/mol
C = 12.01 g/mol
Since your compound is
(
N
H
4
)
2
C
O
3
, you need to multiply the atomic weights by their subscripts. Therefore,
Step 2
N = 14.01 g/mol × 2 =
28.02 g/mol
H = 1.008 g/mol × (4×2) =
8.064 g/mol
O = 16.00 g/mol × 3 =
48.00 g/mol
C = 12.01 g/mol × 1 =
12.00 g/mol
To get the mass of the substance, we need to add all the weights from Step 2.
Step 3
molar mass of
(
NH
4
)
2
CO
3
=
(28.02 + 8.064 + 48.00 + 12.01) g/mol
=
96.09 g/mol
this is a google search and a example i hope is helps to solve