Answer:
Option (2), (3) and (5).
Explanation:
Chemical change: It is a chemical reaction in which arrangement of atoms of one or more than one substance changes to give new substances as a product.Chemical change can be in form of : color change, formation of precipitate, formation of bubbles.
In option (2), bubbles were produced when iron was placed in acid which means gas was released on adding iron to acid.Yes, it is a chemical change.
In option (3), solid that is precipitate is obtained as a product from the reaction between two liquids which means that change in arrangement of atom had taken place.Hence, a chemical change.
In option (5), white substance turned blue when water was added. Color of white solid changes to blue which means that chemical change has taken place.
So, option are (2), (3) and (5) are examples of chemical changes.
Answer:
It is a molecular compound.
Explanation:
Answer:
Hence the evaporation rate in pints per minute is 0.001583.
Explanation:
Now,
1.5 gallons of paint are used.
It has 5% solid, so total 95% of 1.5 gallon can evaporate(only the solvent part will evaporate).
95% of 1.5 gallon=(95/100)*1.5 = 1.425 gallons.
1gallon = 8 pints.
So 1.425 gallons=8*1.425 pints
=11.4 pints.
Evaporation requires 2 hours. That is 3600*2 seconds = 7200 seconds.
So evaporation rate= 11.4 pints/7200 seconds.
=0.001583 pints per second
The answer: less frequency, causing the pitch to be lowered.
This is known as the Doppler effect. When you have an object that is producing sound while moving, the side that it is moving towards to will have waves that will become a bit more squished together, while the other side that it is moving away from will have waves that are spaced a bit more apart from each other. The only determining factor in this is the magnitude of the speed, so the faster the object is moving towards or away from you, then the more severe pitch change the object will have.
In this case, it's just asking in general what would happen if the horn was moving away from you while it was giving off sound waves. Therefore, since it is moving away from you, its sound waves are a bit further apart, resulting in a lowered frequency and pitch.