Here are the answers in order:
1. During a physical change the substance changes physically.
2. The law of conservation of mass is a law stating the conservation of mass cannot be higher than 46mg or lower than 32mg.
3. A hypothesis is a guess that you make before completing a science experiment, it can be considered a law because it is important to know why you are making the guess.
4. During a chemical change the mass is changing colors. This is a representation of a chemical change.
5. Oil is a non-renewable resource, so it cannot demonstrate the conservation of mass.
6. When the color of the substance has changed or when it explodes.
7. Reactants are the objects that react when in a chemical change.
8. If you follow the rule of not going higher than 46mg and not lower than 32mg then it will automatically follow this law.
Chemical Reactions Part One Video:
1. mass
2. erupt-ant
3. reactant
4. object
5. mixtures
6. molecules
7. color changed
Questions again:
1. A chemical reaction
2. A physical change
3. Because if it is no higher than 46mg and no lower than 32mg then it will follow on it's own.
The term isoelectronic atoms means that if the given atoms are neutral, they would have the same number of electrons, which is relative to their sizes. Ions with positive charges are called cations, losing electrons. On the other hand, ions with negative charges are called anions, gaining electrons. The more electrons that the atoms have, the bigger it is in size. Hence, the arrangement of the radii of the atoms would have to be,
e²⁺, d⁺, c , b⁻, a⁻
The arrangement is from smallest to largest.
Explanation:
Lactic acid is formed during the breakdown of glucose. This is sometimes called "blood sugar."
This problem is asking for the percent by mass of hydrogen in hydrofluoric acid. At the end, the answer turns out to be D. 5% as shown below:
<h3>Percent compositions:</h3>
In chemistry, percent compositions are used for us to know the relative amount of a specific element in a compound. In order to do so for hydrogen, we use the following formula, which can also be applied to any other element in a given compound:
Where 
stands for the atomic mass of hydrogen and 
for the molar mass of hydrofluoric acid. In such a way, we plug in the atomic masses of hydrogen (1.01 g/mol) and fluorine (19.0 g/mol) to obtain:
Learn more about percent compositions: brainly.com/question/12247957
