Explanation

In gas chromatography (GC), the mobile phase is a gas, such as helium, nitrogen, or argon, that carries the sample through the column.

The sample is vaporized and separated based on its affinity for the stationary phase, which is typically a solid or liquid coating on the column.

Explanation

The physical methods used to measure physical properties are called Gravimetric analysis methods.

This technique involves measuring the mass of a substance to determine its concentration or quantity.

Explanation

The prefix "hept" stands for 7 carbon atoms.

This is a Greek prefix used in chemistry to denote the number of carbon atoms in a molecule.

Here are some examples:

• Hex- means 6
• Hept- means 7
• Oct- means 8
• Non- means 9
• Dec- means 10

Explanation

• Selective reabsorption primarily occurs in the proximal convoluted tubule (PCT).
• To a lesser extent, in the distal convoluted tubule (DCT), where essential nutrients, water, and ions are reabsorbed back into the bloodstream.

Explanation

Thermoregulation is the ability of an organism to maintain its body temperature within a suitable limit, despite changes in the external environment.

This is a crucial function that allows cells, tissues, and organs to function properly.

Explanation

The gravitational force between two masses is mutual; each mass exerts an equal and opposite force on the other,.

It aligns with Newton's 3rd law of motion: for every action, there is an equal and opposite reaction.

Explanation

To find the pressure, you need to divide the force (20 N) by the area (5 cm^2).

Since 1 cm^2 = 0.0001 m^2, the area in square meters is:

5 cm^2 x (0.0001 m^2/cm^2) = 0.0005 m^2

Now, you can calculate the pressure:

Pressure = Force / Area = 20 N / 0.0005 m^2 = 40,000 N/m^2

Since 1 N/m^2 = 1 Pascal (Pa), you can convert the pressure to N/cm^2:

40,000 N/m^2 x (1 m^2 / 100 cm^2) = 4 N/cm^2

Explanation

The equivalent weight of an element is the mass of the element that reacts with one mole of electrons (or one mole of hydrogen atoms).

For aluminum (Al), the equivalent weight is 9 g.

Atomic weight of Al = 27 g/mol

Valency of Al = 3 (since Al forms Al3+ ions)

Equivalent weight = Atomic weight / Valency

= 27 g/mol / 3

= 9 g

So, 1 g equivalent weight of Al is 9 g!

Explanation

• The empirical formula of hydrogen peroxide (H2O2) is HO.
• The empirical formula is the simplest whole-number ratio of atoms of each element in a compound.
• In this case, the ratio of hydrogen to oxygen is 1:1, which is represented by the formula HO.

Explanation

• The evaporation of water from the leaves, also known as transpiration, creates a negative pressure that pulls water up the xylem from the roots to the leaves.
• This process is known as the transpiration-cohesion theory.