Asubstance that cannot be broken down into simpler substances by chemical means. an element is composed of atoms that have the same atomic number, that is, each atom has the same number of protons in its nucleus as all other atoms of that element. today 117 elements are known, of which 92 are known to occur in nature, while the remainder have only been made with particle accelerators. eighty-one of the elements have isotopes that are stable. the others, including technetium, promethium, and those with atomic numbers higher than 83, are radioactive. see periodic table.

Achemist wants to extract copper metal from copper chloride solution. the chemist places 0.50 grams of aluminum foil in a solution containing 0.75 grams of copper (ii) chloride. a single replacement reaction takes place. (ii) chloride. a single replacement reaction takes place. which statement explains the maximum amount of copper that the chemist can extract using this reaction? a) approximately 0.36 grams, because copper (ii) chloride acts as a limiting reactant b) approximately 1.8 grams, because copper (ii) chloride acts as a limiting reactant c) approximately 0.36 grams, because aluminum acts as a limiting reactant d) approximately 1.8 grams, because aluminum acts as a limiting reactant

How does the presence of oxygen affect the chemical pathways used to extract energy from glucose?

How does a large body of water, such as the ocean, influence climate?