Topic 2 and 3 Review

Which species have the same number of electrons? 
I. S^2– 
II. Cl^– 
III. Ne 

• I and II only
• I and III only
• II and III only
• I, II, and III only

What is the relative atomic mass of an element with the following mass spectrum? 

• 24
• 25
• 26
• 27

Which statement about the species ⁶³Cu²⁺ and ⁶⁵Cu⁺ is correct? 

• Both species have the same number of protons. 
• Both species have the same number of electrons. 
• Both species have the same number of neutrons. 
• Both species have the same electron arrangement. 

What is the electron arrangement of the Mg²⁺ ion? 

• 2,2 
• 2,8 
• 2,8,2 
• 2,8,8 

In the emission spectrum of hydrogen, which electronic transition would produce a line in the visible region of the electromagnetic spectrum? 

• n=2 →n=1 
• n=3 → n=2 
• n=2 → n=3 
• n=∞ → n=1 

Which series is arranged in order of increasing radius? 

• Ca²⁺<Cl^–<K⁺ 
• K⁺<Ca²⁺<Cl^–
• Ca²⁺<K⁺<Cl^– 
• Cl^–<K⁺<Ca²⁺

Which statement is correct for all elements in the same period? 

• They have the same number of electrons in the highest occupied energy level. 
• They have the same chemical reactivity. 
• They have the same number of occupied energy levels. 
• They have the same number of neutrons. 

Which statements about the periodic table are correct? 
 I. The elements Mg, Ca and Sr have similar chemical properties.
II. Elements in the same period have the same number of main energy levels.
III. The oxides of Na, Mg and P are basic. 

• I and II only
• I and III only
• II and III only
• I, II, and III only

Which statements about period 3 are correct?
I. The electronegativity of the elements increases across period 3.
II. The atomic radii of the elements decreases across period 3.
III. The oxides of the elements change from acidic to basic across period 3. 

• I and II only
• I and III only
• II and III only
• I, II, and III only

What happens when sodium is added to water? 
I. A gas is evolved
II. The temperature of the water increases
III. A clear, colourless solution is formed 

• I and II only
• I and III only
• II and III only
• I, II, and III only