The answer should be 12 since 4 x 3 = 12

This is because ammonia is NH^3 and if it has a number before it you multiply it with the rest of the chemical equation.

I hope this helps

6 0

3 years ago

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An index fossil represents a species that lived during

olga nikolaevna [1]

Answer:

Explanation:

an index fossil is a fossil from a very short-lived, geographically widespread species known to exist during a specific interval of geological time.

8 0

3 years ago

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I give Brainliest!

Andrej [43]

Another name for them are called groups or families.

3 0

3 years ago

Use the information for the isotopes of element X to calculate the average atomic mass of X, and identify the element. Isotope A

BigorU [14]

Answer

36.45 u; X = Cl

Explanation:

The atomic mass of X is the <em>weighted averag</em>e of the atomic masses of its isotopes.

We multiply the atomic mass of each isotope by a number representing its relative importance (i.e., its percent of the total).

Set up a table for easy calculation .

0.7577 × 34.969 u = 26.496 u

0.2423 × 36.965 u = <u> 8.9566 u </u>

TOTAL = 36.45 u

X = Cl

5 0

4 years ago

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