Explanation

The complex [Cu(en)2]^+² contains 2 ethylenediamine (en) ligands.

Each en is a bidentate ligand, donating 2 lone pairs, so:

2 ligands × 2 = 4 coordinate bonds → Coordination number = 4

Explanation

In the sentence, "the little one" refers to a person (child), making "one" a noun.

It is a common noun used in place of a name or identity.

Explanation

Barium (Z = 56) → Electron configuration:

[Xe]6s²

Barium's electron distribution:

• K = 2
• L = 8
• M = 18
• N = 18 ⬅ Penultimate shell (4th shell / N-shell)
• O = 8 (valence shell)

The penultimate shell (N-shell) holds 18 electrons in Barium.

Explanation

Step 1: Calculate the molar mass of S8

The atomic mass of sulfur (S) is approximately 32 g/mol. The molar mass of S8 = 8 * 32 = 256 g/mol.

Step 2: Calculate the number of moles of S8

Number of moles = mass of S8 / molar mass of S8 = 64 g / 256 g/mol = 0.25 mol.

Step 3: Calculate the number of molecules of S8

Number of molecules = number of moles * Avogadro's number (NA) = 0.25 * NA.

Step 4: Calculate the number of sulfur atoms

Each molecule of S8 contains 8 sulfur atoms. Therefore, the total number of sulfur atoms = 8 * number of molecules = 8 * 0.25 * NA = 2 * NA = 2NA.

Explanation

The verb "consider" is used without "as" when followed by a noun or adjective complement.

"Foolish" is the correct adjective.

Explanation

The Nearctic region includes North America, where animals like prairie dogs, buzzards, opossums, and mountain lions/dogs are commonly found.

It is one of the major biogeographic realms.

Explanation

The ABO blood group gene is located on chromosome number 9.

It codes for glycosyltransferase enzymes that determine blood type.

Explanation

A probe is a short, single-stranded DNA or RNA sequence that binds to a complementary gene of interest.

It is used to screen genomic libraries for specific genes.

Explanation

Calcium propionate (CH₃CH₂COO⁻Ca⁺) and calcium acetate (CH₃COO⁻Ca⁺) undergo ketonic decarboxylation upon heating.

This reaction forms ethyl methyl ketone (butanone) and releases CO₂.

Explanation

Fringing reefs are directly attached to a shoreline or lie close to the coast of volcanic islands.

They are the most common type of coral reef and develop in the shallow waters near land.