Question

The percentage of abundance of three elements \(X, Y\) and \(Z\) in the earth's crust are about \(27.7\), \(8.3\) and \(46.0\) by mass respectively. \(X, Y\) and \(Z\) are:

• A. O, Si, Al
• B. Al, Si, O
• C. Si, Al, O
• D. Al, O, Si

Hint:

The most abundant element in the earth's crust is oxygen, followed by silicon and aluminium. Their approximate abundances are: \[ O \approx 46\%, \quad Si \approx 27.7\%, \quad Al \approx 8.3\% \]

Answer 1

The Correct Option is C

Step 1: Recall the major elements present in the earth's crust.
The earth's crust contains oxygen, silicon, aluminium, iron, calcium, sodium, potassium, magnesium and other elements.
Among these, the three most abundant elements by mass are: \[ O,\ Si,\ Al \]

Step 2: Match the given percentages with known abundance values.
The approximate abundance of oxygen in the earth's crust is \[ 46.0\% \] The approximate abundance of silicon in the earth's crust is \[ 27.7\% \] The approximate abundance of aluminium in the earth's crust is \[ 8.3\% \]

Step 3: Identify \(X, Y\) and \(Z\).
Given, \[ X=27.7\% \] So, \[ X=Si \] Given, \[ Y=8.3\% \] So, \[ Y=Al \] Given, \[ Z=46.0\% \] So, \[ Z=O \] Therefore, \[ X,Y,Z = Si,Al,O \]

Step 4: Final conclusion.
Hence, the correct sequence is \[ \boxed{Si,\ Al,\ O} \] Therefore, the correct option is \[ \boxed{(3)} \]