When an electric current passes through water, takes place, breaking down the compound into hydrogen and oxygen. a physical change an atomic change a chemical change an elemental change

a chemical change

Explanation:

A physical reaction is defined as the reaction in which a change in shape, size takes place. No new substance gets formed in these reactions.  Example: melting of ice

A chemical reaction is defined as the reaction in which a change in chemical composition takes place.A new substance is formed in these reactions.

Decomposition of water using electric current to produce hydrogen and oxygen is called as electrolysis and is a chemical change.

pure water does not conduct electricity very well. however, when certain substances are dissolved in water, the solution does conduct electricity. you can make a simple device that shows how well a solution conducts electricity. this device uses a flashlight bulb to indicate how well the solution conducts electricity. the better the solution conducts electricity, the brighter the bulb will glow.

explanation:

answer:

the answer is 6 valence electrons.

explanation:

valence is the # of electrons on the outer most shell of an atom.

oxygen has 6.

although, the valency of oxygen is 2, because it only needs to make 2 covalent bonds, or gain 2 electrons, to achieve the stable octet configuration of a noble gas.

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