There is no "generally". For alkali metals (group 1) and alkali earths (group 2) they decrease. For groups 4 to 10 they rise, for group 11 it goes down from copper to silver and then up to gold.
Alkali metals have relatively low melting points compared to the other metals. Their exact melting points depend on the element itself. But it would be useful to note that their melting points decreases down group I.
The main factors that determine how quickly things melt are the material's melting point, the temperature of its surroundings, and the presence of external heat sources. Higher melting points, lower surrounding temperatures, and absence of heat sources will slow down the melting process, while lower melting points, higher surrounding temperatures, and heat sources will speed it up.
The melting point decreases down the group for alkali metals because the metallic bonding weakens as the atomic size increases, resulting in weaker intermolecular forces. For halogens, the melting point increases down the group due to stronger van der Waals forces between larger molecules with increased electron cloud size, resulting in higher melting points.
As you move down a group of noble gases, the atomic size increases, and the number of electron shells also increases. This results in weaker interatomic forces, leading to lower boiling points and melting points. Additionally, the reactivity of noble gases decreases as you go down the group because the outer electron shell becomes further away from the nucleus, making it more difficult for the atoms to form chemical bonds.
The melting and boiling points increase down the group because of thevan der Waals forces. The size of the molecules increases down the group. This increase in size means an increase in the strength of the van der Waals forces.
Alkali metals have relatively low melting points compared to the other metals. Their exact melting points depend on the element itself. But it would be useful to note that their melting points decreases down group I.
In Group 1 (alkali metals), the melting and boiling points decrease as you move down the group due to the increase in atomic size and metallic bonding. In Group 7 (halogens), the melting and boiling points increase as you move down the group due to the increase in atomic size and London dispersion forces.
The trend in melting points as you go down the group of halogens is that they generally increase. This is due to the increasing number of electrons and atomic size which results in stronger van der Waals forces between the atoms, leading to higher melting points.
The melting point of elements generally increases going down a group in the periodic table due to increased atomic size and therefore stronger metallic bonding. However, in the case of Bi, its anomalous behavior is attributed to the presence of inert pairs that reduce metallic bonding. This makes the melting point of Bi lower than Sb, which follows the trend of increasing melting points down the group due to stronger metallic bonding. The same trend applies to Sb having a lower melting point than As due to the weaker metallic bonding in Sb compared to As, which also follows the trend of increasing melting points down the group.
The melting point of magnesium is lower than calcium because although melting points generally decrease down a group, there can be exceptions due to variations in atomic size, packing efficiency, and bonding forces. In this case, the smaller size and stronger metallic bonding in calcium result in a higher melting point compared to magnesium, despite being further down the group.
The general trend of melting points of elements on the periodic table increases from left to right across a period and decreases down a group.
The boiling points of alkaline earth metals generally increase down the group. For example, the boiling point of beryllium is around 2469°C and the boiling point of barium is around 1860°C. The melting points also generally decrease down the group.
The main factors that determine how quickly things melt are the material's melting point, the temperature of its surroundings, and the presence of external heat sources. Higher melting points, lower surrounding temperatures, and absence of heat sources will slow down the melting process, while lower melting points, higher surrounding temperatures, and heat sources will speed it up.
The melting point of magnesium is 650 degrees celcius. It has the lowest melting point among all the group II metals (alkaline earth metals), though the melting points generally decrease down the group - magnesium is an exception and has the lowest melting point among them.
Melting points generally decrease as you go down a group for group I and group II metals. This does not apply to the transition metals. Reactivity of metals increases down a group due to a larger size and less effective charge between the nucleus and valence electrons. Atomic radius increases due to a higher principle number of electrons.
The melting point decreases down the group for alkali metals because the metallic bonding weakens as the atomic size increases, resulting in weaker intermolecular forces. For halogens, the melting point increases down the group due to stronger van der Waals forces between larger molecules with increased electron cloud size, resulting in higher melting points.
As you move down a group of noble gases, the atomic size increases, and the number of electron shells also increases. This results in weaker interatomic forces, leading to lower boiling points and melting points. Additionally, the reactivity of noble gases decreases as you go down the group because the outer electron shell becomes further away from the nucleus, making it more difficult for the atoms to form chemical bonds.