Which of the following statements about soapless detergents is correct? They

A. lather readily with hard water

B. increase the surface tension of water

C. cause hydrolysis of salts in water

D. from a curdy precipitate with soft water

If the relative molecular mass of an element is not a whole number, it can be deduced that the element is

A. naturally radioactive

B. abundant in nature

C. a transition metal

D. an isotopic mixture

The atom of an element X is represented as \(^y_z X\). The basic chemical properties of X depend on the value of

A. Y

B. Z

C. Y - Z

D. Z - Y

The atomic number of chlorine is 17. What is the number of electrons in a chloride ion?

A. 16

B. 17

C. 18

D. 19

A hydrogen atom which has lost an electron contains

A. one proton only

B. one neutron only

C. one proton and one neutron

D. one proton, one electronic and one neutron

Which of the following elements has a ground state electronic configuration with an incomplete penultimate shell?

A. Iron

B. Sodium

C. Aluminium

D. Calcium

The conclusion from Rutherford's alpha-scattering experiment is that

A. atoms are mostly empty space with a small nucleus

B. emissions from radioactive substances consist of three main components

C. there is nuclear pull on orbital electrons

D. electrons are deflected by both magnetic and electric fields

An element Y has the electronic configuration 1s²2s²2p⁶6²3p₄. To what period does it belong in the periodic table?

A. 3

B. 4

C. 5

D. 6

If a metal R forms a compound with the formula R(NO₃)² , the formula of its tetraoxosulphate (IV) is

A. R(SO₄)₂

B. RSO₄

C. R₂SO₄

D. R₂(SO₄)₃

Which of the following decreases when a given mass of gas is compressed to half its initial volume?

A. Average intermolecular distance

B. Frequency of collisions

C. Number of molecules present

D. Atomic radius of each particle