441. Which among the following will be a negative ion?
1. If it has more electrons than protons
2. If it has more electrons than neutrons
3. If it has more protons than electrons
4. If it has more protons than neutrons
Option “1” is correct. Negative ion which is created by an electron gain and it has more electrons than protons.
442. Why metals conduct electricity?
1. Because of low melting point
2. Because of high tensile strength
3. Because of free electrons
4. Because of high atomic density
Option “3” is correct. Metals conduct electricity because of free electrons.
443. The poisonous gas accidentally released in Bhopal Gas Tragedy is –
Option “3” is correct. Bhopal gas tragedy occured on the night of 2–3 December 1984 at the Union Carbide India Limited (UCIL) pesticide plant in Bhopal, Madhya Pradesh. Over 500,000 people were exposed to methyl isocyanate (MIC) gas and other chemicals leaked from UCIL.
444. Release of which among the following is the primary reason for depletion of the ozone layer?
Option “3” is correct. The Chlorofluro carbon formed by chlorine, fluorine and carbon. They are often used as refrigerants, solvents, and for the manufacture of spongy plastics. It is the primary reason for depletion of the ozone layer.
445. Which amongst the following is not a Cation?
1. Aluminium ion
2. Copper ion
3. Sulphate ion
4. Zinc ion
Option “3” is correct. A cation is a positively-charged ion, while an anion is negatively charged. Sulphate is an anion.
446. Which of the following elements has the lowest melting point?
1. Iodine
2. Lead
3. Tin
4. Mercury
Option “4” is correct. Mercury has the lowest melting point. Mercury has a melting point of -37.89F.
447. The common name of sodium bicarbonate is _____.
1. Baking soda
2. Borax
3. Bleach
4. Epsom salt
Option “1” is correct. Sodium bicarbonate is commonly known as baking soda. It is a chemical compound with the formula NaHCO3.
448. Metals react with sodium hydroxide to produce ___________.
1. Oxygen gas
2. Sodium
3. Water
4. Hydrogen gas
Option “4” is correct. Sodium hydroxide reacts with metal to release hydrogen gas. The metal takes the oxygen atom from sodium hydroxide, which in turn takes the oxygen atom from the water, and releases the two hydrogen atoms. The reaction thus produces hydrogen gas.
Option “3” is correct. Redox reaction is the reaction in which oxidation and reduction occurs simultaneously. Rust of iron is nothing but hydrate of iron oxide and iron (III) oxide -hydroxide.
Q. 1. Ribosomes are made up of..
1. Protein and RNA
2. Protein and DNA
3. Carbohydrates
4. Cellulose
Q. 2. Electron transport chain occur at …
1. Protein fibre
2. Cellulose
3. mitochondrial inner membrane
4. Callose
banothshailu@123gemil.come
Which instrument is used to capture the purity of milk?
(A) hydrometer
(B). Isometric
(C). Lacto meter
Lactometer
I Love chemical…it’s my favourite subject..mere iss mein se hmesha hi boht ache marks aate hai….and my interest is also in chemistry…
Protein and RNA
Protein and RNA
vvvwvrww
Very good
Question bank chapter wise for class 12th CBSE 2025 board examination PCB