Explanation

Of the elements listed, aluminum is the one that most commonly exhibits a +3 oxidation state.

Sodium typically shows a +1 oxidation state, and magnesium typically shows a +2 oxidation state.

While iron can exist in a +3 oxidation state (as in iron(III) chloride),

It also commonly exists in a +2 oxidation state (as in iron(II) sulfate), making it a transition metal with variable oxidation states. 

Explanation

Ozonolysis cleaves the double bond in 3-Ethyl-2-pentene, forming two carbonyl compounds.

The double bond is between C2 and C3:

CH3–CH=CH–CH(CH2CH3)–CH3

On ozonolysis, it breaks at the double bond, yielding:

- Ethanal (CH3CHO) from the CH= part

- 3-Pentanone (CH3COCH2CH2CH3) from the rest

Explanation

 The statement "The amount of heat evolved or absorbed in a chemical reaction is the same no matter the reaction takes place in one step or several steps" describes Hess's law. 

Explanation

Methylamine and hydrogen peroxide are liquids due to Hydrogen bonding. 

Hydrogen bonding is a strong type of intermolecular force

That occurs when a hydrogen atom is bonded to a highly electronegative atom 

Like oxygen, nitrogen, or fluorine. In methylamine (CH3NH2)

The nitrogen atom has a lone pair of electrons and can form hydrogen bonds with other methylamine molecules.

Similarly, hydrogen peroxide (H2O2) has hydrogen atoms bonded to oxygen atoms, allowing for hydrogen bonding.

These strong hydrogen bonds hold the molecules together in the liquid state. 

Explanation

Macromolecules are large, complex molecules composed of smaller repeating units called monomers.

Thyroxin, haemoglobin, and insulin are all proteins, which are macromolecules made up of chains of amino acids.

Maltose, on the other hand, is a disaccharide, meaning it's made up of only two sugar units (glucose) and is not considered a true macromolecule. 

Explanation

 Molecular mass of water (H₂O) = 2(1) + 16 = 18 g/mol

- This means 18 grams of water contains 1 mole of water molecules.  

Explanation

In an atom, no two electrons can have the same set of four quantum numbers.

This is known as the Pauli Exclusion Principle.

The four quantum numbers are: 

Explanation

The total energy of a hydrogen atom in its ground state is negative. 

The energy of a hydrogen atom in its ground state is typically represented as -13.6 eV.

A negative energy value indicates that the electron is bound to the nucleus and requires energy to be overcome to escape.

The ground state is the lowest energy level an electron can occupy in a hydrogen atom. 

Explanation

Iso-octane (2,2,4-trimethylpentane) is assigned an octane number of 100 because it resists knocking in engines.

It serves as the standard reference fuel for high-quality performance in internal combustion engines.

Explanation

• A non-metal atom forms an anion (a negatively charged ion) by gaining one or more electrons.
• This means that the atom acquires additional electrons to form a negative ion.