Question

Choose the correct values of $Q,RandS$.

$\underset{92}{238}P\stackrel{\alpha }{\to }Q\stackrel{\beta }{\to }R\stackrel{\beta }{\to }S$.

• A. $\underset{90}{234}Q,\underset{91}{234}R,\underset{92}{234}S$
• B. $\underset{90}{234}Q,\underset{90}{235}R,\underset{90}{236}S$
• C. $\underset{92}{238}Q,\underset{91}{238}R,\underset{90}{238}S$
• D. $\underset{90}{234}Q,\underset{91}{235}R,\underset{92}{236}S$

Answer 1

The correct option is A $\underset{90}{234}Q,\underset{91}{234}R,\underset{92}{234}S$

Atomic number of $Q$ is $92-2=90$.

Mass number of $Q$ is $238-4=234$.

So, ${}_{90}^{234}Q$

Atomic number of $R$ is $90+1=91$.

Mass number of $R$ is $234-0=234$.

So, ${}_{91}^{234}R$

Atomic number of $S$ is $91+1=92$.

Mass number of $S$ is $234-0=234$.

So, ${}_{92}^{234}S$