Explanation
$$\{{}_4^9Be + {}_2^4He \to {}_6^{12}C + {}_0^1n\}$$
Hence option B is correct
Molar mass of $$C_9H_8O_4=9 \times 12+8\times 1+4\times 16$$
$$=180$$ gram/mole
$$180$$ gram $$C_9H_8O_4 \equiv 108$$ gram carbon
$$\therefore x$$ gram $$C_9H_8O_4 \equiv 0.968$$ gram carbon
$$\therefore x=\dfrac{0.968 \times 180}{108}$$
$$= 1.613$$ gram $$C_9H_8O_4$$
Now
$$180$$ gram $$C_9H_8O_4\equiv 8$$ gram Hydrogen
$$\therefore 1.613$$ gram $$C_9H_8O_4 \equiv \dfrac{8\times1.613}{180} $$
$$=0.0717$$ gram '$$H$$'
Option $$(b)$$ correct.
Penultimate orbit i.e. the second last orbit of the atom has 10 electrons and the last orbit which is the 4th orbit has 2 electrons which means the first two orbits K-shell and L-shell are completely filled with 2 and 8 electrons respectively.
Hence, total no. of electrons or the atomic no. of the element is equal to (2+8+10+2) = 22.
Please disable the adBlock and continue. Thank you.