The IUPAC name of the compound CH3-CH(CH3)-CH2-CH3 is: MCQ with Answer and Explanation

Explanation:
Potassium (K) is an alkali metal placed at the very top of the reactivity series. It reacts violently with water and air, requiring storage in kerosene. Gold, silver, and copper are noble or less reactive metals placed at the bottom of the series, often found in the free state.

Explanation:
The root mean square velocity (urms) of gas molecules can be expressed in multiple equivalent ways. It is √(3RT/M) where R is the gas constant, T is temperature, and M is molar mass. Since P = dRT/M (where d is density), it can also be written as √(3P/d). Both formulas are correct.

Explanation:
Silver and gold are noble metals and occur in the free (native) state in nature because they are extremely unreactive (least reactive), not highly reactive. They do not readily combine with oxygen, moisture, or acids. Thus, A is true, but R is false.