Electrides are something of a chemical curiosity. They are ionic materials within which electrons act as anions and they find roles in catalysis and as reducing agents in organic synthesis. They have been shown, both theoretically and experimentally, to exist in several materials at high pressures.

Respiration is a very special form of burning fuel. It involves the burning of sugar with oxygen within the cells of every living organism, to produce the energy needed for all the reactions of life along with water and carbon dioxide as waste products. Respiration is another exothermic reaction.

It should be cleaned before burning due to the following reasons:

• Magnesium very reactive element which rapidly reacts with oxygen in the air to form a white layer of magnesium oxide and this layer will not burn.
• To remove the Magnesium oxide layer from the ribbon which may prevent or slow down the burning of
• magnesium ribbon.
• Unwanted impurities deposited on the magnesium ribbon can be removed and only pure magnesium can be used for the reaction.

Physical Properties of Bases

• Bases taste bitter – There are very few food materials that are alkaline. It is even more important that care be taken in tasting bases. Tasting of bases is more dangerous than tasting acids because of the property of stronger bases to denturate protein.
• Bases release a hydroxide ion in water solution.
• Bases neutralise acids in a neutralization reaction – The word reaction means that an acid plus a base makes water plus a salt. Symbolically where “Y” is the anion of acid “HY”. ‘X’ is the cation of base ‘XOH’ and ‘XY” is the salt in the product, the reaction is

  HY + XOH → HOH + XY

• Bases denature protein – This accounts for the slippery feeling on the hands when exposed to a base. Strong bases that dissolve in water well, such as sodium or potassium lye, are very dangerous because a great amount of the structural material of human beings is made of protein. Serious damage to flesh can be avoided by careful use of strong bases.
• Bases turn red litmus to blue – This is not to say that litmus is the only acid base indicator, but that it is likely the oldest one.

Electronic configuration of an element gives the information of valence electrons and number of shell present in the element. We get the information of group number after knowing valence electrons. 

The number of shells present in an element is equal to the period number. Thus, by knowing electronic configuration we know the group number and period number of an element, and the position of an element in the periodic table.

Elements forming covalent compounds achieve noble gas configuration by sharing electrons within the atoms, unlike ionic compounds which achieve the noble gas configuration either by gaining or losing electrons from the outermost electron shell.  Atoms attain noble gas configuration by gaining or losing electrons in order to satisfy the role of an octet.
 

Atoms want a full outer shell because it completes all the gaps in the outside. With no gaps, other electrons don't want to fit into those spaces. For example, a noble gas like Neon has a full outer shell. It doesn't react with other chemicals because the electrons from other chemicals can't fall in anywhere. Elements forming covalent compounds achieve noble gas configuration by sharing electrons within the atoms, unlike ionic compounds which achieve the noble gas configuration either by gaining or losing electrons from the outermost electron shell.

One of the main reason why the copper vessels lose their shine when exposed to air is due to the passivization.

When copper forms as protective layer of oxidation on the surface for preventing the further deterioration then material would be around the normal condition.

At the surface of vessel, Copper atoms react with the Oxygen atoms in the air forming copper-oxide.

Functional group:
An atom or a group of atoms present in the molecules, which determines the characteristics property of the organic compounds, is called the functional group

Lens is an optical device which converges or diverges the rays of light before transmitting. A lens has similar shape to lentils and genus of lentil is called Lens, thus a lens got its name after the shape and name of genus of lentils. A lens is made by combining at least one part of sphere made of transparent material, generally glass.

Avogadro's Law states:

Equal volumes of gases, at the same temperature and pressure, contain the same number of particles, or molecules.

So, according to Avogadro's law, one mole means 6.022 x 10²³ particles (atoms or molecules, dependent upon the gas). 

Hydrogen gas is diatomic (H₂). Helium gas is monatomic (He). Hence, hydrogen will have twice the number of atoms.

One of the main reasons being that the aluminium sheet is covered in a layer of aluminium oxide which protects it from the moist conditions. 

This layer of aluminium oxide prevents the aluminium from coming into contact with oxygen or air.