General Science — Part 1 MCQs with Explanations

The tree which sends down roots from its branches to the soil is known as banyan tree.

Electric bulb filament is made of tungsten.

Brass gets discolored in air because of the presence of Hydrogen sulphide.

Bromine is a chemical element with symbol Br and atomic number 35. It is the third-lightest halogen, and is a fuming red-brown liquid at room temperature that evaporates readily to form a similarly coloured gas. Its properties are thus intermediate between those of chlorine and iodine.

One such chelate is chlorophyll, the green pigment of plants. In chlorophyll the central ion is magnesium, and the large organic molecule is a porphyrin. The porphyrin contains four nitrogen atoms that form bonds to magnesium in a square planar arrangement.

Graphite is used in pencils.

Almost all metals can form amalgams with mercury, the notable exceptions being iron, platinum, tungsten, and tantalum.

Chemical formula for water is H 2 O.

Incandescent light bulbs are filled with an inert gas like nitrogen, argon, or krypton - so that the filament doesn't catch fire. Early ones were a vacuum.

Sodium carbonate decahydrate, also known as washing soda, is the most common hydrate of sodium carbonate containing 10 molecules of water of crystallization.

The working of Quartz is usually by a crystal oscillator. The Silicon dioxides are the crystals which are piezoelectric and can be further used as speakers and microphones.

Greenhouse gases include: Water vapour (H 2 O), Carbon dioxide (CO 2 ), Methane (CH 4 ), Nitrous oxide (N 2 O), Ozone (O 3 ), and Fluorinated gases such as CFCs, HFCs, PFCs, and SF 6 . Hydrogen (H 2 ) is not a greenhouse gas because it has no permanent electric dipole moment and therefore does not absorb infrared (IR) radiation effectively. The greenhouse effect occurs when gases absorb and re-emit infrared radiation emitted by Earth’s surface. Since hydrogen cannot interact with IR radiation in this way, it does not contribute to atmospheric warming. Furthermore, hydrogen is a very light gas that tends to escape into the upper atmosphere, preventing its accumulation in significant amounts to influence Earth’s temperature.

Bromine (Br), chemical element, a deep red noxious liquid, and a member of the halogen elements, or Group 17 (Group VIIa) of the periodic table.

Diamond is regarded to be the hardest known material in the world.

The variety of coal in which the deposit contains recognizable traces of the original plant material is peat.

Tetraethyl lead is used as Petrol Additive.

Graphite is structurally composed of planes of polycyclic carbon atoms that are hexagonal in orientation. The distance of carbon atoms between planes is longer and therefore the bonding is weaker. Graphite is best suited for lubrication in air. It is a mineral made of loosely bonded sheets of carbon atoms, giving it a slippery texture that makes it a very effective lubricant. This slippery quality also makes graphite a good material for pencil lead because it easily sloughs off onto paper. Graphite is bonded by covalent bond, thus, it is helf by weak intermolecular forces. Since it has weak intermolecular forces, graphite would be slippery and soft enough to act as a lubricant.

The inert gas which is substituted for nitrogen in the air used by deep sea divers for breathing, is Helium.

The gases used in different types of welding would include Oxygen and Acetylene.

Deliquescence, the process by which a substance absorbs moisture from the atmosphere until it dissolves in the absorbed water and forms a solution.

Silicon carbide is used in cutting very hard substances.

Salinity is generally low at the equator and at the poles, and high at mid-latitudes. The average salinity is about 35 parts per thousand. Stated in another way, about 3.5 percent of the weight of seawater comes from the dissolved salts.

When an iron nail gets rusted, iron oxide is formed with increase in the weight of the nail.

Galvanization is the process of applying a protective zinc coating to steel or iron in order to prevent it from rusting.

Among the various allotrope of carbon diamond is the hardest, graphite is the softest.

The group of metals Fe, Co, Ni may best called as transition metals.

Heavy water is a form of water that contains only deuterium rather than the common hydrogen-1 isotope that makes up most of the hydrogen in normal water.

The chemical (ethyl mercaptan) added to the otherwise odourless LPG cooking gas for imparting a detectable smell to the gas is a compound of sulphur.

Hydrogen is the common element in all acids.

Most nonstick pans are coated with polytetrafluoroethylene, also known as Teflon.

Monazite is an important ore for thorium, lanthanum, and cerium. It is often found in placer deposits.

Carbon, diamond and graphite are together called Allotrope.

Used in solid propellants, explosives, fertilizers. Potassium nitrate is the inorganic nitrate salt of potassium. It has a role as a fertilizer.

Temporary hardness can be removed by boiling or by addition of Ca(OH) 2 . Permanent hardness can be removed by the addition of washing soda commonly known as sodium carbonate.

Carbonated water or Soda water is water that has been infused with carbon dioxide gas under pressure. It is carbonic acid. This produces a bubbly drink that's also known as sparkling water, club soda, soda water, seltzer water and fizzy water. With the exception of seltzer water, they usually have salt added to improve the taste.

Bauxite is the most important ore of aluminum which contains only 30–54% alumina, Al 2 O 3 .

Most soluble in water is Sugar.

The chromosphere (literally, "sphere of colour') is the second of the three main layers in the Sun's atmosphere and is roughly 2,000 kilometers deep. It sits just above the photosphere and just below the solar transition region. Helium, the lighter of the noble gases, was the first to be discovered. In fact, this element was first identified in the Sun's chromosphere rather than in the Earth.

The only liquid elements at standard temperature and pressure are bromine (Br) and mercury (Hg). Although, elements caesium (Cs), rubidium (Rb), Francium (Fr) and Gallium (Ga) become liquid at or just above room temperature.

Sodium is the metal stored in kerosene oil in order to prevent it from coming in contact with oxygen and moisture.