Extensive properties useful for identifying a substance because the substance may be present in any . Some properties, such as , aren't useful either.

Extensive properties such as the mass, volume and entropy of systems are additive for subsystems, useful for identifying a substance because the substance may be present in any physical properties. Some intensive properties, such as temperature, refractive index and density, aren't useful either.

Explanation: According to scientific studies, Physical properties of materials and systems can often be classified as being either intensive or extensive, according to how the property changes when the size (or extent) of the system changes. Based on IUPAC classification, an intensive quantity is one whose magnitude is independent of the size of the system whereas an extensive quantity is one whose magnitude is additive for subsystems. This explains the corresponding mathematical ideas of mean and measure, respectively.

answer: - 3.) the oxidation state of nitrogen in no changes from +2 to 0, and the oxidation state of carbon in co changes from +2 to +4 as the reaction proceeds.

solution: - as per the rules, oxidation number of oxygen in its compounds is -2. the sum of oxidation numbers of all the elements of a molecule or compound is zero.

also, the oxidation number in elemental form is zero.

in no, the oxidation number of o is -2 so the oxidation number of n is +2 so that the sum is zero.

similarly, the oxidation number of c in co is +2 and o is -2.

on product side the oxidation number of n is 0 as it is in the elemental form() .

oxidation number of c in carbon dioxide is +4 as there are two oxygen in it and we know that each oxygen is -2.

so, oxidation number of n is changing from +2 to 0 and the oxidation number of c is changing from +2 to +4.

since nitrogen is reduced and hence no is acting as an oxidizing agent. carbon is oxidized and so co is acting as a reducing agent.

so, the right choice is number 3.)the oxidation state of nitrogen in no changes from +2 to 0, and the oxidation state of carbon in co changes from +2 to +4 as the reaction proceeds.

indium, and thallium have three electrons i think