<u>Answer:</u>
Pyrite leaves behind a green-black streak when it is rubbed against an unglazed porcelain plate as a part of the streak test process.
<u>Explanation:</u>
Different minerals produce different coloured streaks when rubbed against a white ceramic or porcelain streak plate. This streak test is done to identify the mineral and distinguish the same from other minerals that look similar in colour and texture.
It must be ensured that the test is done on clean and fresh specimens of the mineral and that there must be no contaminants. Pyrite specimens are usually brass-yellow colour but it leaves a green-black streak when the streak test is done.
<h3>
Answer:</h3>
22.41 seconds longer
<h3>
Explanation:</h3>
- Sound is a longitudinal wave that requires a material medium for transmission hence called a mechanical wave.
- Examples of medium in which sound travels in are water and air.
From the question give;
Speed of sound in air at 20°C is 343 m/s
Speed of sound in water at 20°C is 1,483 m/s
We are given a distance of 10 Km or 10,000 m
We need to finder how much longer it will take for the sound to travel in air.
Time = Distance ÷ Speed
Therefore;
Time taken in Air = Distance ÷ speed of sound in air
= 10000 m ÷ 343 m/s
= 29.15 seconds
Time taken in water = Distance ÷ speed of sound in water
= 10,000 ÷ 1,483 m/s
= 6.74 seconds
Difference in time = 29.15 seconds - 6.74 seconds
= 22.41 seconds
Therefore, it takes 22.41 seconds longer for sound to travel through air than water.
Answer:
0.035 m CH3CH2CH2OH
Explanation:
We know that freezing point is a coligative property hence it depends on the number of solute particles present.
Covalent substances do not break up into ions, hence they do not produce many particles in solution unlike ionic substances. Hence, ionic substances have a far higher freezing point than covalent molecules.
For this reason, 0.035 m CH3CH2CH2OH has the lowest freezing point.
