Explanation

• The nucleus is the solid, central part of a comet, composed of ice and rock.
• It is the source of the comet's activity, including the tail of gas and dust that forms when the comet approaches the Sun.

Explanation

• Mercury is mostly made up of iron.
• It's surface covered with craters.
• It has no atmosphere and no moons.
• It's closest to the sun.
• It's smallest planet.

Explanation

• When a ray of light strikes a brick wall, it is reflected by the wall.
• This is because brick walls are opaque.
• It means they do not allow light to pass through them.
• Instead, the light bounces back, or is reflected, by the wall.

Explanation

• Transparent objects allow light to travel through them without scattering or absorbing any of the light.
• Examples: Glass, water, air, plastic and wrap.

Explanation

• Non-luminous objects do not emit light of their own, but they can reflect, transmit, or absorb light from other sources.
• Examples: Moon, furniture in the room, books, clothes, trees, planets, paper and most solid objects.

Explanation

Friction is the force that generates heat and warmth when surfaces rub against each other.

Explanation

• Electrons exhibit diffraction effects because their de Broglie wavelength is similar to the spacing between atomic layers in a crystal.
• The de Broglie wavelength of an electron is given by λ = h/p, where h is Planck's constant and p is the electron's momentum.
• For electrons in a crystal, this wavelength is typically in the range of 0.1-1 nanometers, which is similar to the spacing between atomic layers in the crystal.
• As a result, electrons interact with the crystal lattice and exhibit diffraction effects, such as bending around corners or passing through the crystal in specific directions.

Explanation

The phenomenon where light of suitable frequency falling on a metal surface ejects electrons is called the "photoelectric effect."

Explanation

Boltzmann's constant (k_B) is a fundamental constant in physics.

The value of Boltzmann's constant is 1.38 × 10^(-23) J/K.

Explanation

Length is a base quantity in the International System of Units (SI), with the unit meter (m).

Volume and Area are derived quantities, calculated using base quantities like length.