3 atoms because 1 atom is of oxygen and 2 atoms are of hydrogen. (Let me know if it’s wrong or right please!)

**Answer:**

**B). Allow efficient gathering of unobservable phenomena.**

**Explanation:**

Surveys are described as the method of gathering information from a specified group of respondents for purposes like research or assessment of the truth of thoughts or opinions associated with a process.

As per the question, one of the most considerable benefits of the survey is that 'it allows the efficient gathering of unobservable phenomena'. **The data associated with phenomena like stated preferences, behaviors, beliefs, and factual information are unobservable and can not be collected through observation but surveys help in doing so** as well as in the assessment of the validity or reliability of the existing propositions about such phenomena. Thus, <u>**option B**</u> is the correct answer.

**Answer:**

<h2>The answer is 2.5 mL</h2>

**Explanation:**

The volume of a substance when given the density and mass can be found by using the formula

From the question

mass of object = 10.02 g

density = 4.08 g/mL

The volume of the object is

We have the final answer as

<h3>2.5 mL to one decimal place</h3>

Hope this helps you

**Answer:**

20

**Explanation:**

17 proton and 20 neutrons

Answer:

V1 = 792.1 ml

Explanation:

The product of pressure and volume is constant when temperature is constant. This relationship is known as Boyle's law.

To answer this, I assume the chlorine gas will behave as a perfect gas. In reality this is not completely true.

P1*V1 = P2*V2

Given:

P1 = 681 mm Hg

V1 = ?

P2 = 992 mm Hg

V2 = 543.8 ml

V1 = ( P2 * V2 ) / P1

V1 = (992 *543.8 ) / 681

V1 = 792.143318649046 ml

V1 = 792.1 ml