Scientists use the chemical and physical properties of matter to differentiate substances. Which of the following is a chemical property? (A) A starch sample turns blue when introduced to iodine
(B) Gold's property of malleability allow it to be shaped into a ring.
(C) Salts exhibit electrical conductivity.
(D) A metal is identified by its density.

a.) A starch sample turns blue when introduced to iodine

Explanation:

A is a chemical change whereas the other answers would be physical changes.

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.

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