Identify the pairs of metals and their ores from the following.
`{:("Group A","Group B"),("a. Bauxite","i.Mercury"),("b. Cassiterite","ii. Aluminium"),("c. Cinnabar","iii. Tin"):}`

Identify the addition polymers from the following: i. Terylene ii. Polypropene iii. Polyacrylonitrile iv. Nylon-6 v. Polyvinyl chloride

Write pairs of isotones and oned pair of mirror-nuclei from the following : ._5^10B,_6^12C,_13^27Al,_6^11C,_14^28Si

Match the following Match Group A (Glands) with Group B (location ) and Group C (Hormones).

Match the following How are the items in groups A, B and C interrelated?

Match the following : From the groups B and C , choose the proper words , for each of the words in group A .:

Identify the INCORRECT statements from the following. (i)Lysosomal enzymes do not digest their own membrane proteins. (ii)Accidental release of lysosomal enzymes in limited amount does not harm the cell because pH of cytosol is near neutral. (iii) Any insufficiency in secretion of lysosomal enzymes leads to disorders e.g. in genetic disorder- Klinefelter syndrome. (iv) Due to insufficiency of protease brain gets impaired resulting from accumulation of fats.

Explain the following: A metal 'X' acquires a green colour coating on outer surface on exposure to air. (i) Identify the metal 'X' and name the process responsible for this change. (ii) Name and write chemical formula of the green coating formed on the metal. (iii) List two important methods to prevent the process.

Mendeleev predicted the existence of certain elements not know at that time. He named two of these elements as eka-aluminium and eka-silicon. a. Name the elements which have taken the place of these elements. b. Mention the group and period of these elements in the modern periodic table. c. Which one of these two elements is a metalloid? d. How many valence electrons are present in eka-silicon? e. Eka-aluminium forms a chloride. What is its formula?

The pair of simultaneous equations from the following is…………………(1) 2x+2y=7 (2) 4x+3z=9 (3) 3y+4z=8 (4)3z+9x=18 a)1 and 2 b)2 and 3 c)3 and 4 d)2 and 4