Chemistry Chapter: Hydrogen and Oxygen

Hydrogen is the most abundant element in the universe.

Molecular hydrogen appears as $H_2$ in high atmosphere layers.

Hydrogen's position is at the top of the periodic table with atomic number 1.

Hydrogen is a diatomic, colorless gas that is flammable and reactive with oxygen.

Hydrogen is a biogenic element and a vital component of many organic compounds.

The instrument is often soluble in water, which impacts its usage.

The instrument is highly reactive and can form many compounds.

Used in breathing apparatus for mammals or plants, crucial for respiration.

Applied in air-related occupations such as firefighting and aviation.

The instrument is used in various welding and cutting metals.

Elemental oxygen (O₂) found in air, supporting combustion.

Oxygen exists in gaseous, liquid, and solid forms.

Supports combustion and is present in many compounds, primarily water.

Oxygen exists as O₂, meaning two oxygen atoms bonded together.

Hydrogen is used with oxygen for welding and cutting, achieving flame temperatures of 3000 °C.

Hydrogen serves as a fuel for spacecraft propulsion.

Hydrogen is utilized in the production of chemicals like HCl (hydrochloric acid) and NH3 (ammonia).

Hydrogen is used in the processing of vegetable oils, often for hydrogenation.

Hydrogen is stored in pressure vessels that are color-coded for safety and identification.

A gas used for advertising and signaling lights.

A gas used for welding shielding and lamp filling.

A gas that fills light bulbs, lasting 85-100 hours.

A gas that absorbs X-rays and is used in lamps.

A radioactive gas found in the Earth's crust.

Collective name for elements in group 18 with filled valence shells.

They are non-reactive and have filled valence shells.

The second most abundant element in the universe; light, non-flammable, and inert.

Helium is the 12th most abundant element in the atmosphere.

Found in meteorological balloons for research, and deep-sea expeditions.

Elements in group VIIA of the periodic table, including fluorine, chlorine, bromine, and iodine.

Halogens form diatomic molecules: F₂, Cl₂, Br₂, and I₂ when bonded.

Halogens have 7 electrons in their outermost shell, making them reactive.

Fluorine is the most reactive halogen and is used in making refrigerants.

Halogens readily accept an electron to form a negative ion (anions).

Chlorine is used for disinfection and as an offensive agent in WWI.

Bromine is primarily used in the photographic industry.

Iodine is a dark purple solid that sublimes at room temperature.

Iodine vapour is used for disinfection but can be harmful if misused.

Astatine is known for being a radioactive element.

Second most abundant metal in Earth's crust.

Located in the Earth's core, contains iron and nickel.

Found as iron-rich ores in crustal rocks.

Iron ore with chemical formula Fe₃O₄.

Iron is shiny, malleable, and ductile; a transitional metal.

Group 1 elements (besides hydrogen) that are reactive metals with one outer electron.

Soft, silvery-white solids with low melting and boiling points, forming compounds naturally.

Specific colors produced by alkali metal ions when heated in a flame: Na^+ is yellow, Li^+ is red, K^+ is violet.

Alkali metals have lower density compared to most metals, often floating on water.

Iodine is vital for health, found in minerals and often ingested as sodium chloride (table salt).