Explanation

"To help" is in its infinitive form, which is the base form of the verb preceded by "to."

It expresses the purpose or intent of the action in the sentence.

Explanation

 Let's solve the equation:

(3/2)x - 5/2 = 1/2

Add 5/2 to both sides:

(3/2)x = 1/2 + 5/2

(3/2)x = 6/2

(3/2)x = 3

Multiply both sides by 2/3:

x = 3 × (2/3)

x = 2

Explanation

Reactivity is a chemical property that describes how easily a substance undergoes chemical change.

It indicates how a substance reacts with others to form new substances.

Explanation

The idiom "up to his eyes" means someone is extremely busy or deeply involved in something.

In this context, it shows the colleague has had a heavy workload.

Explanation

48: 1, 2, 3, 4, 6, 8, 12, 16, 24, 48

64: 1, 2, 4, 8, 16, 32, 64

120: 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 20, 24, 30, 40, 60, 120

The highest common factor (HCF) among these numbers is: 8

Explanation

B - A represents the set of elements that are in B but not in A.

The correct notation is: {x | x ∈ B and x ∉ A}

Explanation

In an endothermic reaction, energy is absorbed, so the products have more energy than the reactants.

This results in a temperature drop in the surroundings.

Explanation

To convert degrees to radians:

  Radians = Degrees × (π / 180)

  45 × (π / 180) = π/4

Explanation

Frequency is calculated using the formula:

f = v / λ

where v = 8 m/s (speed), λ = 2.5 m (wavelength)

So, f = 8 / 2.5 = 3.2 Hz

Explanation

In the lab, oxygen gas is prepared by heating potassium chlorate (KClO₃) in the presence of manganese dioxide (MnO₂) as a catalyst.

MnO₂ speeds up the decomposition of KClO₃ without being consumed.