German Silver (also known as New Silver, Nickel Brass, etc) is a copper alloy with nickel and often zinc. The usual formulation is 60% copper, 20% nickel and 20% zinc. It is named for its silvery appearance, but it contains no elemental silver unless plated.

Correct Option: C

German Silver (also known as New Silver, Nickel Brass, etc) is a copper alloy with nickel and often zinc. The usual formulation is 60% copper, 20% nickel and 20% zinc. It is named for its silvery appearance, but it contains no elemental silver unless plated.

The ability of radioactivity to pass through materials is called its penetrating ability. Penetrating ability depends on the size of the radioactive particle. Alpha particles are the biggest, beta particles are very much smaller and gamma rays have no mass. Ultraviolet rays have less energetic photons compared to gamma rays and x-rays and a lower penetration power. Gamma rays are the most penetrating of the radiations.

Correct Option: D

The ability of radioactivity to pass through materials is called its penetrating ability. Penetrating ability depends on the size of the radioactive particle. Alpha particles are the biggest, beta particles are very much smaller and gamma rays have no mass. Ultraviolet rays have less energetic photons compared to gamma rays and x-rays and a lower penetration power. Gamma rays are the most penetrating of the radiations.

The red, orange, yellow, green, blue and purple colors exploding in the night sky during a pyrotechnic festival are created by the use of metal salts. Barium chloride provides green colour to firework displays. Metal salts that are commonly used in firework displays include: strontium carbonate (red), calcium chloride (orange), sodium nitrate (yellow), barium chloride (green fireworks) and copper chloride (blue fireworks).

Correct Option: C

The red, orange, yellow, green, blue and purple colors exploding in the night sky during a pyrotechnic festival are created by the use of metal salts. Barium chloride provides green colour to firework displays. Metal salts that are commonly used in firework displays include: strontium carbonate (red), calcium chloride (orange), sodium nitrate (yellow), barium chloride (green fireworks) and copper chloride (blue fireworks).

Transition metals are used directly as catalysts in the anti–pollution catalytic converters in car exhausts. For example, expensive transition metals such as Platinum and rhodium are used in the catalytic converters in car exhausts to reduce the emission of carbon monoxide and nitrogen monoxide, which are converted to the non–polluting gases nitrogen and carbon dioxide. 2NO(g) + 2CO(g) ⇒ N2(g) + 2CO₂(g)

Correct Option: C

Transition metals are used directly as catalysts in the anti–pollution catalytic converters in car exhausts. For example, expensive transition metals such as Platinum and rhodium are used in the catalytic converters in car exhausts to reduce the emission of carbon monoxide and nitrogen monoxide, which are converted to the non–polluting gases nitrogen and carbon dioxide. 2NO(g) + 2CO(g) ⇒ N2(g) + 2CO₂(g)

In 1967, based on Einstein defining the speed of light as the most constant dimension in the universe, the International System of Units isolated two specific wave counts from an emission spectrum of caesium-133 to co-define the second and the meter. Since then, caesium has been widely used in highly accurate atomic clocks. Among alkali metals, cesium has lowest ionization energy and hence it can show photoelectric effect to the maximum extent.

Correct Option: B

In 1967, based on Einstein defining the speed of light as the most constant dimension in the universe, the International System of Units isolated two specific wave counts from an emission spectrum of caesium-133 to co-define the second and the meter. Since then, caesium has been widely used in highly accurate atomic clocks. Among alkali metals, cesium has lowest ionization energy and hence it can show photoelectric effect to the maximum extent.