Answer:
d. Radon-222
Explanation:
²²⁶₈₈Ra → ²²²₈₆Rn + ⁴₂He
Alpha particle is a helium nucleus with mass number 4 and atomic number 2. According to the law of conversation of mass, the sum of the mass number and atomic number must be equal on both side of the reaction.
Since the mass number of Ra is 226 and that of He is 4. The mass number of the unknown element must be 226 - 4 = 222.
Since the atomic number of Ra is 88 and that of He is 2. The atomic number of the unknown element must be 88 - 2 = 86.
Now looking in the periodic table Radon is the only element with atomic number 86.
Answer:
the difference in electronegativity is so large (2.04) that the bonding electrons spend almost all their time on the nitrogen atom.
Explanation:
Because calcium loses 2 electrons to become Ca2+, and nitrogen gains 3 electrons to become N3−, you need two calcium atoms and three nitrogen atoms in order to form a neutral compound.
Answer:
Water does not remain when an insoluble substance is added
Answer: 60.7 g of 
will be formed.
Explanation:
To calculate the moles :
The balanced chemical reaction is
is the limiting reagent as it limits the formation of product and 
is the excess reagent.
According to stoichiometry :
6 moles of produce = 4 moles of
Thus 2.68 moles of will produce=
of
Mass of 
Thus 60.7 g of will be formed by reactiong 60 L of hydrogen gas with an excess of
