Answer:
Explanation:
The atomic number tell us the number of protons and neutrons in the nucleus of an atom. in other words ,each element has a unique number that identifies how many protons are in one atom of that element example, all hydrogen atoms, and only hydrogen atoms, contain one proton and have an atomic number of 1.
Liquid because 20 Celsius is 68 Fahrenheit<span />
5. B air is a mixture of many elements, but is not a chemically fused.
6. B Beef stew, composition varies throughout.
7. A. They can be chemically separated into their component elements, but they are all homogenous, and as such, have constant composition, which differs from the components properties, as the components must undergo a chemical change to become compounds.
Answer:B) a reactant that undergoes reduction
Explanation:
Oxidation reaction is defined as the reaction in which a substance looses electrons. The oxidation state of the substance increases during oxidation.
Reduction reaction is defined as the reaction in which a substance gains electrons. The oxidation state of the substance gets reduced during reduction.
Overall reaction: 
The substance M which itself gets oxidized, reduces other and is called as reducing agent. The substance N which itself gets reduced, oxidizes other and is called as oxidizing agent.
Explanation:
Hydrogen does not obey the octet rule. Boron does not always
obey the octet rule and in fact forms Lewis acids such as BF3 which
only has 6 electrons.
