Answer:
Pure substance B) Consists of a single element or type of compound.
Homogeneous A) Mixture that has its different components mixed evenly within the substance.
Heterogeneous D) Mixture that has its different components mixed unevenly within the substance.
Solution C) Liquid homogeneous mixture in which the solute is distributed evenly within the solvent.
Explanation:
Pure substances are a form of matter with definite constant composition and distinct properties. They consist of a single element or type of compound, as can be seen in its formula. Na, O₂, NaCl and H₂O are examples of pure substances.
When 2 or more pure substances are mixed together they form a mixture. If the mixture has its different components mixed <u>evenly</u> within the substance it is a homogeneous mixture. Whereas if the mixture has its different components mixed <u>unevenly</u> within the substance it is a heterogeneous mixture. The different parts observable in a heterogeneous mixture are known as phases.
In liquid homogeneous mixtures, we can recognize one or more substances that are in lower proportions (solutes) and one substance that is in greater proportion (solvent). This kind of mixture is known as a solution.
Most animals obtain their nutrients by the consumption of other organisms. At the cellular level, the biological molecules necessary for animal function are amino acids, lipid molecules, nucleotides, and simple sugars. However, the food consumed consists of protein, fat, and complex carbohydrates.
The answer is <span>(3) 3 × 12.4 hours
</span>
To calculate this, we will use two equations:


where:
<span>n - number of half-lives
</span>x - remained amount of the sample, in decimals
<span>

- half-life length
</span>t - total time elapsed.
First, we have to calculate x and n. x is <span>remained amount of the sample, so if at the beginning were 16 grams of potassium-42, and now it remained 2 grams, then x is:
2 grams : x % = 16 grams : 100 %
x = 2 grams </span>× 100 percent ÷ 16 grams
x = 12.5% = 0.125
Thus:
<span>

</span>




It is known that the half-life of potassium-42 is 12.36 ≈ 12.4 hours.
Thus:
<span>

</span><span>

</span>

Therefore, it must elapse 3 × 12.4 hours <span>before 16 grams of potassium-42 decays, leaving 2 grams of the original isotope</span>
<u>Answer:</u> The molar mass of unknown triprotic acid is 97.66 g/mol
<u>Explanation:</u>
To calculate the molarity of acid, we use the equation given by neutralization reaction:

where,
are the n-factor, molarity and volume of triprotic acid
are the n-factor, molarity and volume of base which is NaOH.
We are given:

Putting values in above equation, we get:

To calculate the molecular mass of solute, we use the equation used to calculate the molarity of solution:

We are given:
Molarity of solution = 0.0077 M
Given mass of triprotic acid = 0.188 g
Volume of solution = 250 mL
Putting values in above equation, we get:

Hence, the molar mass of unknown triprotic acid is 97.66 g/mol
If the solid is a metal, yes. Most solids on the periodic table are metals