<u>Answer:</u>
<em>B. A and B</em>
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<u>Explanation:</u>
1. Solids have a definite volume, definite size and definite shape
2. The particles present in a solid are very closely packed since the intermolecular forces between them are very strong. The molecules do not move apart.
3. Melting point is the temperature at which solid changes into a liquid.
4. When a solid is heated to the melting point the intermolecular forces are overcome by the energy and the molecules present in it moves from its fixed position to take its liquid state which is called as melting.
Explanation:
Formula for black body radiation is as follows.

where, P = power emitted
A = surface area of black body
= Stephen's constant = 
As area is given as 1.0
. Converting it into meters as follows.
(as 1 m = 100 cm)
= 
It is given that P = 201 watts. Hence,
= 
= 
T = 
= 8862.5 K
Thus, we can conclude that the temperature of the surface is 8862.5 K.
Answer:
health issues and physical encounters
Answer : The final temperature of the mixture is 
Explanation :
In this problem we assumed that heat given by the hot body is equal to the heat taken by the cold body.


where,
= specific heat of iron = 
= specific heat of water = 
= mass of iron = 39.9 g
= mass of water = 
= final temperature of mixture = ?
= initial temperature of iron = 
= initial temperature of water = 
Now put all the given values in the above formula, we get


Therefore, the final temperature of the mixture is 
Answer : behavior in a field experiment is more likely to reflect real life because of its natural setting, i.e. higher ecological validity than a lab experiment
Explanation: