Answer:
17
Two clear liquids mix and form a
white solid
18.chemical
A pot of water begins to
boil
19.Physical
the rest im usure on.
It should be noted that when a reaction is occurring in a test tube, heat transmitted to the surroundings when Molecules collide with the glass, and the glass molecules then transmit that energy to the outside.
<h3>What is heat?</h3>
Heat can be regarded as a form of energy which is energy that is been transferred as a result of difference in temperature.
In the case above, Molecules collide with the glass, and the glass molecules then transmit that energy to the outside which is an exothermic reaction.
Therefore, option B is correct.
Learn more about heat at:
brainly.com/question/12072129
<h3>
Answer:</h3>
1.2 × 10⁻⁸ mol Pb
<h3>
General Formulas and Concepts:</h3>
<u>Math</u>
<u>Pre-Algebra</u>
Order of Operations: BPEMDAS
- Brackets
- Parenthesis
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
<u>Chemistry</u>
<u>Atomic Structure</u>
- Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.
<u>Stoichiometry</u>
- Using Dimensional Analysis
<h3>
Explanation:</h3>
<u>Step 1: Define</u>
[Given] 7.2 × 10¹⁵ atoms Pb
<u>Step 2: Identify Conversions</u>
Avogadro's Number
<u>Step 3: Convert</u>
- [DA] Set up:

- [DA] Multiply/Divide [Cancel out units]:

<u>Step 4: Check</u>
<em>Follow sig fig rules and round. We are given 2 sig figs.</em>
1.19562 × 10⁻⁸ mol Pb ≈ 1.2 × 10⁻⁸ mol Pb
The H+ concentration in the lake has increased as a result of the acid rain.
The original pH of the lake was 7, which mean the water is neutral, but due to the acid rain, it drops to 5. This means, that the water has become acidic and how have more hydrogen ion. The H+ concentration in the lake has 100 times compares with its original pH.