Post Utme Chemistry Past Questions and Answers

Question 621:

Use the section of the periodic table below to answer questions
\begin{array}{|l|l|l|l|l|l|l|l|}
\hline 1 & & & & & & & \(2 L\) \\
\hline \(3 \mathrm{G}\) & \(\mathrm{M}\) & 5 & 6 & 7 & \(8 \mathrm{~d}\) & \(9 \mathrm{E}\) & \\
\hline 11 & \(\mathrm{X}\) & \(13 \mathrm{~K}\) & 14 & 15 & \(16 \mathrm{~T}\) & 17 & 18 \\
\hline
\end{array}
Which of the letters indicate an alkali metal and a noble gas respectively,

A. M and E
B. G and E
C. R and E
D. G and L

Question 622:

Use the section of the periodic table below to answer questions
\begin{array}{|l|l|l|l|l|l|l|l|}
\hline 1 & & & & & & & \(2 L\) \\
\hline \(3 \mathrm{G}\) & \(\mathrm{M}\) & 5 & 6 & 7 & \(8 \mathrm{~d}\) & \(9 \mathrm{E}\) & \\
\hline 11 & \(\mathrm{X}\) & \(13 \mathrm{~K}\) & 14 & 15 & \(16 \mathrm{~T}\) & 17 & 18 \\
\hline
\end{array}

Which letter represents a non-metal that is a solid at room temperature?

A. T
B. R
C. J
D. X

Question 623:

Which of the following statements is FALSE about isotopes of the same element?

A. They have the same number of electrons in their outmost shells
B. They have different atomic masses
C. They have the same atomic number and the same number of electrons
D. They have the same atomic number but different number of electrons

Question 624:

Helium is often used in observation balloons because it is

A. Light and combustible
B. Light and non-combustible
C. Heavy and combustible
D. Heavy and non-combustible

Question 625:

Neutralization involves a reaction between H30+ and ____________

A. Cl-
B. OH-
C. NO3
D. CO32-