Year 1972
if I'm not wrong :)
<span>So we want to know what statement is an accurate description of vibrations. So humans can hear sound frequencies from 20-20000 Hz. Below 20 Hz is infra sound and above 20000 Hz is ultra sound. Humans cant hear both infra sound and ultra sound so the correct answer is A.</span>
Answer:
Both substance will melt and become a solution.
Explanation:
When a mixture of iron filings (black substance) and sulphur powder (yellow substance) are heated in a test tube under a bunsen burner, usually they will undergo a chemical reaction where they will melt to form a new solution of ferrous sulphide.
Thus, we can say what happens is that both substances melt to form a solution.
