)what is the mass percent of a solution prepared by dissolving 18.9 grams of an unknown solid into 39.5 grams of water?

32.4%

Explanation:

Step 1: Given data

Mass of the solute = 18.9 g

Mass of the solvent = 39.5 g

Mass of the solution = Mass of the solute + Mass of the solvent = 58.4 g

Step 2: Calculate the mass percent of the solute in the solution

We use the following expression.

the answer is c i believe

the transfer of heat by electromagnetic radiation is called thermal radiation . it is usually carried out by electromagnetic waves in an energy range just below the visible spectrum, which is the infrared range.

so the answer would be radiation.

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