Tim adds a magnesium strip to a beaker containing hydrochloric acid. He notices that bubbles immediately start to form. When the bubbling subsides, he notices that the magnesium strip is gone and that the beaker now only contains a clear solution. As the hydrochloric acid breaks apart to dissolve the magnesium, the hydrogen atoms ________ to form a ________ bond.
A) share electrons, covalent
B) exchange electrons, ionic
C) require electrons, atomic
D) combine electrons, metallic
The answer is A. Here is the reaction.
Mg + 2HCl ==> MgCl2 + H2
H has 1 electron and can be represented by H. as a symbol.
The other H. looks the same. They combine to form H:H. The bubbles are hydrogen gas.
D) combine electrons, metallic
The correct answer is A) share electrons, covalent.
In order to understand why, let's break down the process that is happening when the hydrochloric acid reacts with the magnesium strip.
When the magnesium strip is added to the hydrochloric acid (HCl), it reacts to produce magnesium chloride (MgCl2) and hydrogen gas (H2). This reaction is a classic example of a redox reaction, where one substance is oxidized (loses electrons) and another substance is reduced (gains electrons).
Mg (magnesium) is a metal and tends to lose electrons, while H (hydrogen) is a non-metal and tends to gain electrons. When the magnesium strip is submerged in the hydrochloric acid, the magnesium atoms lose two electrons, becoming Mg2+ ions. These electrons are then gained by two hydrogen atoms from the hydrochloric acid, each forming a single covalent bond with one of the hydrogen atoms. This results in the formation of hydrogen gas, which is released as bubbles.
So, in this reaction, the hydrogen atoms are sharing electrons with the chloride ions in the hydrochloric acid to form covalent bonds. The correct answer is A) share electrons, covalent.