Answer:
40%
Explanation:
Calculate the percent of the mass that is carbon:
<span>a. x and y are atoms of the same element.
If both atoms contain the same amount of protons, they are always the same element.
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<span>An element is made of only one kind of atom, while a compound contains the atoms of two or more elements. For example, gold is made of only one kind of atom, so it is an element, but water is a mix of hydrogen and oxygen, so it is a compound.</span>
Carbon dioxide is a compound. Oxygen is an element. A compound is 2 or more elements chemically combined. An element is a pure substance. A mixture is combining two or more different compounds/elements.
