Water is an element.

Water boils in an electric kettle in 15 min after being switched on . Using the same main supply , should the length of the heating element be increased or decreased if the water is to be boiled in 10 min ? Why ?

Which is the last element in the series of the actinoids? Write the electronic configuration of this element. Comment on the possible oxidation state of this element.

Which is the last element in the series of the actinods? Write the electronic configuration of this element. Comment on the possible oxidation state of this element.

An element reacts with oxygen to give a compound with a high melting point. This compound is also soluble in water. The element is likely to be (a) calcium (b) carbon (c) silicon (d) iron

Calculate the mass percentage of each element in water (H_(2)O)

Name a trace element which increases the absorption of water and calcium

An electric kettle used for heating water has two heating elements. One raises the temperature of water by Delta theta in time t_(1) and another in time t_(2) . Assuming no loss of heat , find the time taken to raise the temperature by Delta theta . (i) When heating elements are connected in series. (ii) When heating elements are connected in parallel.

Classify the following substances into element, compound and mixture. (i) Brass (ii) Distilled water

Name an element from group 2 which forms an amphoteric oxide and a water soluble sulphate.