CBSE Class X – Science Chemistry + Biology + Physics Exam (Full Syllabus)

The mole ratio of hydrogen and oxygen gases liberated during electrolysis of water is 2:1 by volume. In a decomposition reaction, a compound is broken down into its simpler forms. During electrolysis, water is broken down into oxygen gas and hydrogen gas due to the passage of electric current through it.

This is an example of two types of reaction: Redox reaction because oxidation (removal of hydrogen) and reduction (addition of hydrogen), both are happening simultaneously._x000D__x000D_Displacement reaction as it involves displacement by oxygen of H atoms from a compound (NH₃) with an other atom.

Baking soda’s formula does not show any relationship water molecules.

Clove oil is an olfactory indicator. These the substances which give one type of odour in acidic medium and a diferent odour in basic medium so a visually challenged student favours to use clove oil as an acid-base indicator.

Metals generally do not show dullness. Metals such as gold and silver are usually shiny comparatively than dull.

It is the element which possess tetravalent property and thus form covalent compound.

Non-metals form acidic oxides. The element with atomic number Ǫ is a nonmetal (nitrogen). Rest three elements with atomic numbers.

Anaerobic respiration (in absence of oxygen) in yeast is known as fermentation as ethanol (alcohol), carbon dioxide and 2 ATP molecules of energy is produced from glucose

Menopause is a natural process at the age of 40s or 50s in case of human females. Menopause occurs when a women has not have her menstrual cycle for 12 consecutive months and can no longer become pregnant naturally.

Umbilical cord is responsible for exchange of nutrients, oxygen and waste products between the embryo and the mother’s body .

Reproduction is one of the important characteristic function of living things. it is essential for the continuity of species for generations to continue.

One pair called the sex chromosomes is odd, not always being a perfect pair. Women have a perfect pair mismatched pair, in which one is a normal-sized X while the other is a short one called Y (XY).

The wavelength of red light is maximum in the spectrum, it’s penetration power in the air is maximum and so we can see red colour from farther distances. thus, danger signal uses red colour

In order to get the working of heater properly, fused wire of higher rating must be used.

Flemings Right hand rule gives the direction of the induced current. Stretch the thumb, forefinger and middle finger of right hand so that they are perpendicular to each other.

All are the causes to occur overloading