Explanation

Let's analyze the sequence:15, 14, 12, 9,?

The pattern seems to involve subtracting decreasing amounts:

15−1=14

14−2=12

12−3=9

Following this pattern, the next subtraction should be:

9−4=5

Thus, the missing term is 5.

Explanation

During crossing over in meiosis I, homologous chromosomes exchange different segments, leading to genetic recombination and increased variation.

Explanation

Explanation

The oxidation of secondary alcohols produces ketones.

This reaction involves the loss of a hydrogen atom from the hydroxyl (-OH) group and a hydrogen atom from the alpha carbon (the carbon atom bonded to the -OH group),

Forming a double bond between the alpha carbon and the oxygen atom.  

Explanation

The functional group for a ketone is a carbonyl group (C=O), where the carbonyl carbon is bonded to two other carbon atoms.

The general formula for a ketone is R–C(=O)–R' or CnH2nO;

Where the central carbon atom is double-bonded to an oxygen atom and single-bonded to two alkyl or aryl groups (R and R'). The simplest ketone is propanone (acetone), with the formula C₃H₆O.  

Explanation

Adding more SO₂ – This would increase the yield by shifting the equilibrium toward the product (Le Chatelier's principle).

Explanation

Explanation

The momentum 

𝑝 of a photon is given by the equation:

𝑝=ℎ/𝜆 

where:

h is Planck's constant,

λ is the wavelength of the photon.

Since photons are massless, their momentum is not related to mass but to their wavelength.

Explanation

The photoelectric effect does not occur if the frequency of the incident light is below the threshold frequency.

The threshold frequency is the minimum frequency required for the incident photons to have enough energy to eject electrons from the surface of the material.

If the frequency is below this value, no electrons are emitted, regardless of the light intensity.

Explanation

Given the conditions:

a>b

b>c

d>a

We can draw the following relationships:

From a>b and b>c, we know that a>c.

From d>a, we know d>a and, since a>b and a>c, it follows that d>b and d>c.

So, the only valid option is b