Answer:
There are 40 electrons in one atom of Zirconium.
Explanation:
Note: The word is not zicronium, it is Zirconium.
Answer:a quantum absorption of energy
Explanation:
Bohr’s model explains the spectral lines .While the electron of the atom remains in the ground state, its energy is unchanged. When the atom absorbs one or more quanta of energy, the electron moves from the ground state orbit to an excited state and when the atom relaxes back to a lower energy state, it releases energy that is again equal to the difference in energy of the two orbits.
Answer : The correct option is (c) 
Explanation :
The given balanced chemical reaction is,

From the balanced chemical reaction, we conclude that
As, 3 moles of
react to give 2 mole of 
So, 1 mole of
react to give
moles of 
Thus, the conversion factor needed to convert the number of moles of
to the number of moles of
produced is 
Hence, the correct option is (c) 
Answer:
c. the heart
all the rest actually will excrete, the heart is in a closed system so contributes to excretory organs but doesn't actually do it barring an accident
Explanation:
Answer:
1st question: The moon is closer to Earth so it is easier to see and visit.
2nd question: The moon has a week/month cycle instead of a day/night cycle.
3rd question: The corona
Explanation: