14 The Periodic Table

How does metallic property change down the group

Down the group, the number of electron shells increase so valence electron is further away from the nucleus. The electrostatic forces of attraction between the nucleus and valence electron is weaker. It is easier to lose the valence electron and hence metallic property increases.

How does metallic property change down the period

Metallic property decreases down the period. The number of valence electrond increases, but the number of of electron dheld remains the same. The tebdency to lode valence electrons to achieve stanle electronic configuration decreases. Hence, metallic property decreases.

How do alkali metals compare to other metals

They have lower density, lower melting point and are softer.

How does the melting point change down group 1

The melting point decreases down the group. There is an increase in atomic size due to the increase in number of electron shells and the valence electrons are further away from the nucleus. The electrostatic forces of attraction between the positive nucleus and the negative electrons decrease. Less energy is taken in to overcome the weaker electrostatic forces of attraction, hence the melting point decreases.

How does density change down group 1

Density increases down the group

Why are alkali metals electrical conductors

They have a giant metallic lattice structure of positive cations surrounded by a sea of delocalised electrons which act as mobile charge carriers to conduct electricity.

How does reactivity change down group 1

Down the group, the number of electron shells increase, resulting in an increase of atom size. The valence electron is further away from the positively charged nucleus. Less energy is taken in to overcome the weaker electrostatic forces of attraction between the valence electron and the nucleus. Hence it is easier to lose the valence electron and reactivity increases.

what are group 1 reactions

Alkali metal + water → metal hydroxide + hydrogen, alkali metal + steam → metal oxide + hydrogen

Why do group 1 metals burst into flames when reacting with water

Oxygen is readily available in the air, hudrogen acts as a fuel, the reaction is exothermic, producing heat

How does the boiling point change down the group 17

Group 17 elements have a simple covalent structure. Down the group, the atomic radius of the elements increases due to the increase of electron shells. There is a larger surface area in contact between molecules and the intermolecular forces of attraction between molecules gets stronger. Hence, more energy is absorbed to overcome the stronger intermolecular forces of attraction between halogen molecules.

How does reactivity change down group 17.

Down the group, the number of electron shells increases, resulting in an increase in atomic size. Valence electrons of other atoms will be further from the positively charged nuclei of the halogen. More energy is required for the halogen atoms to gain electrons. Hence, reactivity decreases.

Halogen reaction

Halogen + reactive metal → halide salt

Are group 18 gases soluble in water

No

How does boiling point change down group 18

Down the group, the boiling point increases as there is an increase in relative atomic mass of the elements, hence forced of attraction betwen atoms increases. More energy is taken jn to overcome the stronger forced of attraction, hencd increase in boiling point.

How does density change down group 18

Down the group, density increasses as there is an increase in relative atomic mass of elements. According to thr Avogrados Law, at rtp, one mole of any gas will occupy a fixed volume of 24dm3. Since density is mass per unit volume, the relative atomic mass of elements increases due while the volume stays the same, density will increase down the group.