Answer is 10 units of water molecules.
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C. Something that can be observed or measured while changing the identity of the substance
Correct answer is magnesium bromide. This is an ionic compound with metal forming a positive ion - K+ and halogen forming a negative ion - Br-. When group 7 element form ions they have a suffix -ide. Bromine is the element and when it forms a negative ion bromine is called bromide with the suffix.
Magnesium gives 2 electrons and bromine can take only 1 electron, therefore 2 bromine atoms are needed. Therefore magnesium forms ionic bonds with 2 bromine atoms.
The compound is called magnesium bromide
Paper is shredded, the paper is physically being shredded, iron rusting is due to oxygen reacting with it, gas is burned releases and odor which is a sign of chemical, shirt being bleached is chemical reaction.