Answer:
Chemical indicator, any substance that gives a visible sign, usually by a color change, of the presence or absence of a threshold concentration of a chemical species, such as an acid or an alkali in a solution. An example is the substance called methyl yellow, which imparts a yellow color to an alkaline solution.
Thank you for posting your question here. To answer that question, an acid is a substance that contains hydrogen. It usually has a sour taste and also can able to neutralize alkali and reddening blue litmus paper. The hydrogen that it contains can be replaced by a metal.
Answer:
0.693 (you can round it up if you want to)
Explanation:
Density= mass ÷ volume
54.2 ÷ 78.1 = 0.693
I hope this helped☺
To covert from moles to atoms times the number of moles by Avogadro's Number (6.022×10²³)
4.0 × 6.022×10²³ = 2.4088×10^24