An illustration shows the periodic table of elements with elements arranged in increasing order of atomic number in 18 columns (groups) and 7 rows (periods). The electronegativity of elements increases from left to right, across a period. The hydrogen on the left is included in group with medium electronegativity. Also, fluorine is shown as element with highest electronegativity.

Question

Which element is most likely to replace hydrogen in a displacement reaction?

(1 point)
Responses

oxygen (O)
oxygen (O)

bromine (Br)
bromine (Br)

lithium (Li)
lithium (Li)

helium (He)

Answer 1

In a displacement reaction, a more reactive element typically replaces a less reactive element in a compound.

Hydrogen has a moderate electronegativity, and in terms of reactivity, it is generally more reactive than elements like oxygen (O) and bromine (Br) but less reactive than alkali metals like lithium (Li).

Helium (He) is a noble gas and does not participate in chemical reactions under normal conditions.

Among the options given:

• Oxygen (O) is a non-metal and can react with hydrogen but is not typically considered to replace it in a displacement reaction.
• Bromine (Br) is less reactive than hydrogen and would not typically replace it.
• Lithium (Li) is an alkali metal and is more reactive than hydrogen, making it the most likely candidate for replacing hydrogen in a displacement reaction.

Therefore, the element that is most likely to replace hydrogen in a displacement reaction is lithium (Li).