Answer:
c Example 1 represents a liquid and Example 2 represents a solid.
Explanation:
Example 1: Young children dancing slowly around one another
The young children dancing slowly around one another can be pictured as the flow of liquid. In liquids, the molecules are held about weakly and they slide on top of each other. They are held by weak attractive forces. This is clear picture of a liquid.
Example 2: Newborn babies sitting in their given spots in a crib
This is clear example of a solid. In a solid the molecules are held about a fixed spot. The attractive forces in liquids is very great and the molecules therein do not move about randomly.
Answer:
The grating spacing is 
Explanation:
From the question we are told that
The wavelength is 
The angle is 
The order of the spectrum is 
Generally in grating grating the condition for maxima to occur is

where d is the grating spacing
making d the subject of the formula

Substituting values


Answer: The statement is true
Explanation:
The half-life of a radioactive isotope is the time taken for half of the total number of atoms in a given sample of the isotope to decay.
For instance
The half-life of radium is 1622 years. This means that if we have 1000 radium atoms at the beginning, then at the end of 1622 years, 500 atoms would have disintegrated, leaving 500 undecayed radium atoms
Thus, the statement is true
In a distillation model, it is better to let the cold water enter the bottom of the condenser and exit at the top because this can lead to a better cooling effect.
When water enters from the bottom, they will stay longer in the condenser, thus the vapor in the condenser can be cooled back into liquid faster.
In addition, this method can also save the amount of water used, since they water can stay longer in the condenser.