Explanation

The elements in group VIIA of the periodic table are called halogens.

This group consists of the following elements:

• Fluorine (F)
• Chlorine (Cl)
• Bromine (Br)
• Iodine (I)
• Astatine (At)
• Tennessine (Ts)

Explanation

The most stable hydrocarbon among the given options is trans-2-butene. 

Stability in alkenes:

• The stability of alkenes is primarily determined by the degree of substitution at the double bond.
• More substituted alkenes are generally more stable. 

Trans vs. Cis Isomers:

• In the case of 2-butene, the trans isomer is more stable than the cis isomer.
• This is because in the trans configuration, the alkyl groups on either side of the double bond are oriented away from each other, minimizing steric hindrance.
• In the cis configuration, the alkyl groups are on the same side, leading to steric repulsion and less stability. 

Explanation

Ethylene glycol (HOCH2CH2OH) is a 1,2-diol, and both periodic acid (HIO4) and lead tetraacetate (Pb(OAc)4)

They are strong oxidizing agents capable of cleaving the carbon-carbon bond between the adjacent hydroxyl groups in a glycol

Resulting in the formation of carboxylic acids. In the case of ethylene glycol, this would yield oxalic acid (HOOC-COOH). 

Explanation

Affinity for oxygen refers to how readily an element or compound combines with oxygen.

Magnesium (Mg) is a highly reactive alkaline earth metal that readily loses its two electrons to form a positive Mg2+ ion.

This ion then readily combines with oxygen to form magnesium oxide (MgO), demonstrating a strong affinity for oxygen. 

Explanation

NMR spectroscopy provides detailed information about the connectivity of atoms within a molecule,

Including the types of carbon and hydrogen atoms present, their relative positions, and the presence of functional groups.

This level of detail allows for a comprehensive understanding of a molecule's structure, making it significantly more informative than the other options. 

Explanation

Graham Edgar introduced the octane number concept in the 1920s to measure the anti-knocking quality of fuels.

He established iso-octane (100) and n-heptane (0) as reference points for rating fuels.

Explanation

• CH3-OH is the molecular formula for methanol, which is an alcohol.

Key Points:

• CH3-CHO is the molecular formula for acetaldehyde, which is an aldehyde.
• CH3-CH2-O-CH3 is the molecular formula for diethyl ether, which is an ether.
• HCOOH is the molecular formula for formic acid, which is a carboxylic acid.

Explanation

• The atomic number 19 corresponds to the element Potassium (K).
• The electron configuration of Potassium is: 1s² 2s² 2p⁶ 3s¹
• Which can be simplified to: 2, 8, 8, 1.

Explanation

The 6th period of the modern periodic table contains 32 elements.

This period is known as the "extended" period and includes elements from the Lanthanide series. 

It is the longest period of the periodic table

Explanation

At room temperature, H₂ (hydrogen) has the lowest density among Ne (neon), N₂ (nitrogen), and CO (carbon monoxide). 

Density is directly proportional to molar mass, meaning the gas with the lowest molar mass will have the lowest density.

Hydrogen has the lowest molar mass among the listed gases, making it the least dense.