Answer : The mass of sample is, 267.5 grams.
Explanation :
Density : It is defined as the mass of a substance contained per unit volume.
Formula used :

Given:
Volume of Pb = 
Density of Pb = 
Now put all the given values in the above formula, we get the mass of Pb.


Therefore, the mass of sample is, 267.5 grams.
N=
l=
m(l)=
m(s)=
start with H^+ (no electrons) , then adding 5 electrons will be 1s2 2s2 2p1
so for the 5th electron
n = 2
l = 1
ml = -1
ms = 1/2
LaChatelier's Principle
LaChatelier's Principle is a principle stating that if a constraint (such as a change in pressure, temperature, or concentration of a reactant) is applied to a system in equilibrium, the equilibrium will shift so as to tend to counteract the effect of the constraint.
Answer:
1) conduction
2) Radiation
Explanation:
Conduction is a mode of heat transfer by which heat energy is transferred through a material, the average position of the particles of the material remaining the same.
Radiation is a process of heat transfer by which heat is transferred from a hotter to a cooler point without any intervening medium.
The pan used to fry the egg is a conductor of heat hence heat can pass through it by conduction thereby enabling the eggs to cook.
Heat can travel without an intervening medium hence Zoe feels hot near the stove. This ability of the heat to travel without an intervening medium is called radiation.
C) Nucleus...... Hope it helps, Have a nice day :)