Explanation

The drum of a Photostat machine (also known as a xerox machine) is made of a material called selenium,

That is a photoconductive element.

This means that when exposed to light

It becomes conductive, allowing the machine to transfer the image onto the paper. 

Explanation

Silicon is an element found in glass, cement, China Clay and Quartz. 

Silicon is a chemical element with the symbol Si and atomic number 14.

MUG 10-12-2022

ND5-07-2023

Explanation

Joseph Priestly discovered oxygen on August 1, 1774.

The most abundant element in the Earth's crust is oxygen, making up 46.6% of Earth's mass

Explanation

Oxy-acetylene welding is a very common welding process.

Gases used in welding and cutting processes include:

• shielding gases such as carbon dioxide, argon, helium, etc.
• fuel gases such as acetylene, propane, butane, etc.

oxygen, used with fuel gases and also in small amounts in some shielding gas mixtures

Explanation

Table salt is the granulated white salt seen in most saltshakers. Table salt is typically mined from underground deposits.

Table Salt is commonly known as Sodium chloride

MUG 11-12-2022

Explanation

Aluminum is the most abundant metal in the Earth's crust, and the third most abundant element therein, after oxygen and silicon.

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Explanation

Light Emitting Diodes are light sources that are energy efficient and can be made in a variety of colors.

Gallium is a soft, silvery metal used primarily in electronic

circuits, semiconductors, and light-emitting diodes (LEDs).

LEDs are comprised of compound semiconductor materials, which are made up of elements from group III and group V of the periodic table

SH5-8-2023

Explanation

Lead is commonly used as a shield against gamma rays.

Due to its high density.

It effectively absorbs and blocks gamma radiation.

Explanation

Compound: a substance that is made up of more than one type of atom bonded together.

Additional Information:

Explanation

Nuclear power plants primarily use a specific type of uranium 235 for nuclear fission

because its atoms are easily split apart.

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Uranium's most stable isotope, uranium-238,

has a half-life of about 4,468,000,000 years.

Uranium-238 is not fissile, but is a fertile isotope,

because after neutron activation it can produce plutonium-239, another fissile isotope.