NCFE Practice Spring

What is the chemical formula for magnesium bromate? 

• MgBr

• MgBr₂

• MgBrO₃

• Mg(BrO₃)₂

Which of these elements has the greatest atomic radius? 

• H

• N

• Cl

• Cs

A newly synthesized ionic compound is placed in water to make an aqueous solution. Which best describes the new ionic solution? 

• The ionic solution conducts electricity. 

• The ionic solution dissolves nonpolar solutions. 

• The ionic solution cannot conduct electricity. 

• The ionic solution is a neutral solution. 

Which occurs if an electron transitions from n = 5 to n = 2 in a hydrogen atom? 

• Energy is absorbed, and visible light is emitted.

• Energy is released, and visible light is emitted. 

• Energy is released, and visible light is not emitted. 

• Energy is absorbed, and visible light is not emitted. 

When a gamma ray is emitted by an element, what happens to the atomic mass and the atomic number? 

• The atomic mass stays the same, and the atomic number stays the same. 

• The atomic mass changes, and the atomic number stays the same. 

• The atomic mass stays the same, and the atomic number changes. 

• The atomic mass changes, and the atomic number changes. 

How does a single covalent bond between two carbon atoms compare to a double covalent bond between two carbon atoms?

• A single covalent bond is stronger and has a longer bond length than a double covalent bond.

• A single covalent bond is stronger and has a shorter bond length than a double covalent bond.

• A single covalent bond is weaker and has a shorter bond length than a double covalent bond.

• A single covalent bond is weaker and has a longer bond length than a double covalent bond.

How do the three isotopes Sn-116, Sn-118, and Sn-119 differ? 

• Sn-116 has 166 neutrons, Sn-118 has 168 neutrons, and Sn-119 has 169 neutrons. 

• Sn-116 has 116 neutrons, Sn-118 has 118 neutrons, and Sn-119 has 119 neutrons. 

• Sn-116 has 66 neutrons, Sn-118 has 68 neutrons, and Sn-119 has 69 neutrons. 

• Sn-116 has 50 neutrons, Sn-118 has 52 neutrons, and Sn-119 has 53 neutrons. 

Which molecule contains a triple bond? 

• F₂

• O₂

• Cl₂

• N₂

Which element has 8 valence electrons? 

• potassium

• oxygen

• helium

• neon

Which best represents the electron configuration for an atom of iron? 

• [Ar]4s²3d⁶ 

• [Ar]4s² 

• [Ar]3s²3p⁶3d⁸ 

• [Ar]4s²4d⁶