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

The chemical reaction between dilute hydrochloric acid and granulated zinc is represented as follows:_x000D__x000D_Zn + 2HCl → ZnCl₂ + H₂↑

A double displacement reaction involves a displacement of two ions of two different compounds that results in the formation of new compounds. Here, only in reaction (ii), ions of both reactants are exchanged and two entirely different compounds are formed

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

Aluminum is more reactive than iron, it displaces iron from ferrous sulphate solution. The green colour of ferrous sulphate solution slowly changes to brown as iron is formed.

Reaction between an acid and an alcohol results in the formation of ester, and the reaction is named as esterification.

A cation is formed by loss electrons from the atom of an element which acquires positive charge due to the presence of greater number of protons as compared to that of electrons.

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

Eka-aluminum (later identified as gallium) has a valency of 3. Hence, the oxide would be of the molecular formula E₂O₃. Other options have a different valency of E.

Digestion of food starts in mouth by salivary amylase. From here it enters into the stomach via oesophagus The simpler substances formed by chemical digestion are then absorbed by small intestinal villi.

Repeated division of an organism to produce many daughter cells simultaneously.

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).

In series, Rs = R1 + R2 = 10 Ω

Constant temperature makes the resistivity constant which made resistance constant. Constant resistance again made the Ohms law applicable. Thats why Ohms law is applied only at constant temperature. It is like the conditions apply of the law.

It is given that the current carrying conductor is held in exactly vertical direction.  In order to produce a clockwise magnetic feld around the conductor, the current should be passed in the conductor from top towards bottom.