Chemistry Lecture Flashcards: Elemental Properties and Hydrogen

Comprehensive practice flashcards covering basic element facts, properties and isotopes of hydrogen, chemical production methods, and color classifications of hydrogen.

What is the most abundant element in the Universe?

Hydrogen

What is the most abundant element in Earth's crust?

Oxygen

What is the most abundant metal in Earth's crust?

Aluminium

What is the most abundant element in Earth's atmosphere and its abundance percentage?

Nitrogen ($78\%$)

Which element is listed as having the highest number of isotopes?

Tin ($Sn$)

Which element is the most reactive metal, and which is the most reactive non-metal?

The most reactive metal is Caesium ($Cs$), and the most reactive non-metal is Fluorine ($F$).

What was the first metal used by humans?

Copper ($Cu$)

Which metal has the highest density at room temperature?

Osmium

Which metal is the lightest metal?

Lithium

Which metal has the highest boiling and melting point?

Tungsten ($W$)

Which element has the lowest boiling and melting point?

Helium

Which metal is the most ductile, and which metal is the best conductor?

Gold is the most ductile metal, and Silver is the best conductor.

Which metal is the softest metal and is also used in atomic clocks?

Caesium ($Cs$)

What are the physical properties and relative density of Hydrogen gas?

It is a colourless, odourless, and tasteless gas that is lighter than air, possessing the lightest known density.

Why is Hydrogen gas not used in balloons despite being lighter than air?

Because it catches fire easily.

What are the three isotopes of Hydrogen?

Protium, Deuterium, and Tritium.

What are the structural properties and stability of Protium?

It is the most abundant isotope of hydrogen, containing 1 proton, 0 neutrons, and 1 electron (mass number = 1). It is stable and non-radioactive.

What are the structural properties and occurrence of Deuterium?

It contains 1 proton, 1 neutron, and 1 electron (mass number = 2). It is stable, non-radioactive, and found in heavy water ($D_2O$).

What are the structural properties and applications of Tritium?

It contains 1 proton, 2 neutrons, and 1 electron (mass number = 3). It is a radioactive isotope used in nuclear research and fusion studies.

How is the number of neutrons in an atom calculated?

$$\text{Number of neutrons} = \text{Mass number} - \text{Atomic number}$$

What reactions occur at the anode and cathode during the electrolysis of water?

Oxidation (loss of electrons) occurs at the anode, while reduction (gain of electrons) occurs at the cathode.

What chemical equation represents the Water-Gas (Steam) Process?

$$C + H_2O \rightarrow CO + H_2$$

What is the difference between Coal Gasification and Coal Liquefaction in terms of output and Hydrogen usage?

Coal Gasification produces syngas ($CO + H_2$ or $CO_2 + H_2$), whereas Coal Liquefaction produces liquid fuel (petrol, gasoline, diesel, etc.) and consumes $H_2$.

What chemical equation represents the hydrolysis of calcium carbide?

$$CaC_2 + H_2O \rightarrow C_2H_2 + Ca(OH)_2$$

What is Green Hydrogen?

Hydrogen produced by the electrolysis of water using renewable energy such as solar and wind power.

What is Blue Hydrogen?

Hydrogen produced from natural gas using carbon capture & storage (CCS) to reduce $CO_2$ emissions.

What is Grey Hydrogen?

Hydrogen produced from natural gas without carbon capture, resulting in significant $CO_2$ emissions.

What is the difference between Black Hydrogen and Brown Hydrogen?

Black $H_2$ is produced from coal through gasification with high levels of $CO_2$ emissions, while Brown $H_2$ is produced from lignite or brown coal through gasification with high $CO_2$ emissions.

What is Pink Hydrogen?

Hydrogen produced by the electrolysis of water using electricity generated from nuclear energy.

What is Yellow Hydrogen?

Hydrogen produced by the electrolysis of water using electricity from the conventional power grid.

What is White Hydrogen?

Naturally occurring hydrogen found in underground geological formations or extracted directly.