Answer:
c
Explanation:
because heat is taken in in sublimation.
Answer:
a). The energy released by the alpha decay of 222 Rn is to 218 Po :
= 5.596 MeV
b).The energy of the alpha particle is 5.5 MeV
c) The recoil energy of Po = 0.096 MeV
Explanation:
The equation for the alpha decay of Rn to Polonium is:

The energy of the decay process can be calculated using:

= Change in the mass
Mass of Po = 218.008965 u
Mass of He = 4.002603 u
Mass of Rn = 222.017576 u
= mass of Po + mass of He - mass of Rn
= 4.002603 + 218.008965-222.017576
= - 0.006008


= -5.596 MeV
<u><em>The negative sign means energy is released during the process.</em></u>
b) The energy of the alpha particle is :



= 5.494 MeV
= 5.5 MeV
c).
Recoil energy: When the parent nucleus is at rest before the decay then , there must be the some recoil of daughter nucleus to conserve the momentum.This is termed as recoil energy.
<u><em>The energy of the recoil polonium atom :</em></u>
The formula for recoil energy is :
<em>The total energy - the kinetic energy</em>
<em>= 5.596 - 5.5 </em>
<em>= 0.096 MeV</em>
The equation would be NaBr
In the compound potassium nitrate (KNO3), the atoms within the nitrate ion are held together with COVALENT bonding, and the potassium ion and nitrate ion are held together by IONIC bonding.
A covalent bond, also called a molecular bond, is a chemical bond that involves the sharing of electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs. Covalent bond is formed between two non-metals.
Ionic bonds form when one atom gives up one or more electrons to another atom. It is the complete transfer of valence electron(s) between oppositely charged atoms. Ionic bond is formed between metal (electropositive element) and non-metal(electronegative element)
In nitrate ions the Nitrogen (N) and Oxygen (O) both are non-metals and it involves the sharing of electron pairs between N and O atoms, so the bonding in Nitrate (
) ion is covalent bonding.
In potassium nitrate , Potassium (K) is a metal and Nitrate (
) ion is non-metal and it involves the complete transfer of valence electron between oppositely charged atoms (K+) and (
). So the bonding between Potassium and Nitrate is Ionic bonding.
NOTE : Bonding between Non-metals is Covalent bonding.
Bonding between Metal and Non-metals is Ionic bonding.
Answer:
The snow absorbed radiant energy to produce a physical change.
Explanation: