Ask question

Ask question

All categories

Amiraneli [1.4K]

3 years ago

15

The recommended daily requirement of calcium is1,000 mg. Tap water in a Midwestern city contains approximately 150 mgCa/L. A per

son living in the city who drinks two liters of water in oneday would receive ________ percent of his/her RDA of calcium.
A. 3
B. 7.5
C. 15
D. 30

1 answer:

madam [21]3 years ago

5 0

The answer is D. 30 percent

You might be interested in

What explanation accounts for the observation that the mass of the products in reaction #1 (open system) were not equal?

Anna007 [38]

Answer:

The law of conservation of mass states that matter can not be created or destroyed in a chemical reaction.

Explanation:

5 0

2 years ago

Calculate the ph of sweater which has a hydrogen ion concentration of 1 times 10 to the power of 8

telo118 [61]

Answer:

The pH of the sweater containing Hydrogen ion concentration

$[H^{+}]=1\times 10^{-8}$ is

<u>8</u>

<u></u>

Explanation:

pH = It is the negative logarithm of activity (concentration) of hydrogen ions.

pH = -log([H+])

Now, In the question the concentration of [H+] ions is :

$[H^{+}]=1\times 10^{-8}$

$pH = -log(1\times 10^{-8})$

use the relation:

$log(10^{-a})=a$

$pH= -(-8)$

pH = 8

Note : <em><u> 1 times 10 to the power of 8 must be" 1 times 10 to the power of -8"</u></em>

If the concentration is

$[H^{+}]=1\times 10^{8}$

Then pH = -8 , which is not possible . So in that case the pH calculation is by other method

5 0

3 years ago

HELP!!! WRITE THE CORRECT ISOTOPE NOTATION FOR EACH OF THE FOLLOW:

kakasveta [241]

The answer is 4 an atom

4 0

2 years ago

1.31 times 10^-22 / 6.6262 times 10^-34

victus00 [196]

The first answer is -.595454 the second answer is -1.9488

4 0

3 years ago

If a substance cannot be separated <br> physically it is?

MArishka [77]

Its an element Im pretty sure

3 0

3 years ago

Read 2 more answers