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Because although the covalent bonds between the elements are strong, there are only weak forces between the molecules so they have low melting points
Barrett Kunze
Wiki User
∙ 14y agoIt's because of the properties of a covalent bond.
1. The covalent bond is a compound between two or more non-metals.
Non-metals have low melting points.
2. it tends to not form crystals which is crystal lattice.
It can be easily broken.
3. The attractions are weak.
(which can also be the one of the reasons why it isn't in a crystal form.)
I wish this small words help you.
As you may recall, ionic compounds have very high melting and boiling points because it takes a lot of energy for all of the + and - charges which make up the crystal to get pulled apart from each other. Essentially, when we have an ionic compound, we need to break all of the ionic bonds in order to make it melt.
On the other hand, when we have covalent compounds we don't need to break any bonds at all. This is because covalent compounds form distinct molecules, in which the atoms are bound tightly to one another. Unlike in ionic compounds, these molecules don't interact with each other much (except through relatively weak forces called "intermolecular forces"), making them very easy to pull apart from each other. Since they're easy to separate, covalent compounds have low melting and boiling points.
Wiki User
∙ 11y agoThe melting points and boiling points of molecular covalent compounds (ones with discrete molecules) are lower than ionic solids and giant molecule covalent compounds like (silica, SiO2) because the forces that attract them together in the solid and the liquid states (van der waals, hydrogen bonding and dispersion forces) are weaker than ionic (or covalent) bonds.
Wiki User
∙ 11y agoThe melting points and boiling points of molecular covalent compounds (ones with discrete molecules) are lower than ionic solids and giant molecule covalent compounds like (silica, SiO2) because the forces that attract them together in the solid and the liquid states (van der waals, hydrogen bonding and dispersion forces) are weaker than ionic or covalent bonds.
Wiki User
∙ 12y agoA molecule is a group of atoms which are sharing electrons with one another through covalent bonds. Because the sharing results in a lower energy state, the atoms are more stable together than alone. When a sample of a molecular substance is looked at, say water (H2O), within the substance each molecule is being attracted to other molecules. These attractive forces are called intermolecular forces and they are much weaker than covalent bonds or ionic bonds.
Wiki User
∙ 12y agoBecause the bonds between atoms are so weak, they do not have to be heated to high temperature to make the atoms separate and become liquids.
Wiki User
∙ 11y agoBecause although the covalent bonds between the elements are strong, there are only weak forces between the molecules so they have low melting points
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Do simple molecular substances have high or low melting and boiling points?
Yes, molecular solids have relatively low melting points.
Do non polar covalent compounds have high or low melting points?
No they have high melting and boiling points. Don't get confused with simple molecular structures such as water and carbon dioxide which have simple covalent structures. When you heat them you are overcoming the forces BETWEEN THE MOLECULES (intermolecular/van der waals forces of attraction), NOT the actual covalent bonds themselves, like the bond betwen the C and either O in carbon dioxide.
Why do simple covalent bonds have low melting and boiling point?
It's due to the facts that simple covalent bonds like single bonds are weaker and longer than others bonds with tighter interactions like pi bonds (double bonds) or ionic bonds. Once the heat is turned up it excites the electrons to move from their bonded positions and the bond breaks
Why molecular substances with weak intermolecular forces have low melting points?
The cause is just this weak intermolecular force, ease to be broken.
Does covalent structures have high or low boiling points?
It depends on the type of structure; simple covalent structures (like water) generally have low boiling points, while giant covalent structures (like diamond) have high boiling points.
Do simple molecular substances have high or low melting and boiling points?
Yes, molecular solids have relatively low melting points.
Do non polar covalent compounds have high or low melting points?
No they have high melting and boiling points. Don't get confused with simple molecular structures such as water and carbon dioxide which have simple covalent structures. When you heat them you are overcoming the forces BETWEEN THE MOLECULES (intermolecular/van der waals forces of attraction), NOT the actual covalent bonds themselves, like the bond betwen the C and either O in carbon dioxide.
Describe General trend in physical appearance of the elements in period 3?
Sodium, magnesium and aluminum are all good conductors of electricity. Silicon is a semiconductor.Sodium, magnesium and aluminum all have metallic structures, which accounts for their electrical conductivity and relatively high melting and boiling points.The nuclei of the atoms gets more positively charged.Melting and boiling points rise across the three metalsSilicon has the highest melting point.Phosphorus, sulphur, chlorine and argon are simple molecular substances with only van der Waals attractions between the molecules. Their melting or boiling points will be lower than those of the first four members of the period which have giant structures.These four substance with simple molecular structures also do not conduct electricity.
What are some properties of molecular compounds?
Simple molecular structures like H2O and CO2 have the following properties: 1) Physical state: usually liquids and gases at room temperature due to weak intermolecular forces 2) Melting and boiling points: low (below 2000 C) melting and boiling points due to weak intermolecular forces 3) Electrical conductivity: cannot conduct electricity because there are no free electrons 4) Solubility: insoluble in water, but soluble in organic substances such as petrol Macromolecular structures such as diamond and SiO2 have the following properties: 1) Physical state: hard solids at room temperature due to the many strong covalent bonds holding the atoms together 2) Melting and boiling points: high melting and boiling points due to the many strong covalent bonds that must be broken before the substance can change state 3) Electrical conductivity: cannot conduct electricity because there are no free electrons 4) Solubility: insoluble
Why do simple covalent bonds have low melting and boiling point?
It's due to the facts that simple covalent bonds like single bonds are weaker and longer than others bonds with tighter interactions like pi bonds (double bonds) or ionic bonds. Once the heat is turned up it excites the electrons to move from their bonded positions and the bond breaks
Why do substances made up of simple molecules have low points?
Substances made up of simple molecules have low melting points because there are strong bonds between the atoms in the molecule, but weak bonds holding the molecules together. Therefore, the intermolecular forces break fairly easily, due to the fact that they are weak and the covalent bonds making up the molecule do not break because they are strong. This means that, due to the weak intermolecular forces breaking down easily, simple molecular substances have low melting and boiling points.
Why molecular substances with weak intermolecular forces have low melting points?
The cause is just this weak intermolecular force, ease to be broken.
Does covalent structures have high or low boiling points?
It depends on the type of structure; simple covalent structures (like water) generally have low boiling points, while giant covalent structures (like diamond) have high boiling points.
What are some properties of molecular bonding?
Simple molecular structures have very strong covalent bonds, but the intermolecular forces are very weak. This means they can be parted easily, which means they are not very hard or strong and can have thus a very low melting point. This means that at room temperature, they are usually gases or liquids.Since they have no ions either, they cannot conduct electricity very well. Simple molecular solids such as ice, tends to melt easily and dissolve in organic solvents.
What is element with giant structures?
simple molecules are bonds between non-metals and elements, or in some cases, non-metals and non-metals. Things like Water, CO2, I2 are simple moleculars. The single molecules of simple moleculars are held together through covalent bonds, the intermolecular forces that hold together many bonds are weaker, thus simple moleculars have low melting/boiling points. Giant Metallics are bonds between metals, such as Zinc Magnesium, and have strong bonds among and between atoms, with high melting/boiling points and ability to conduct electricity.
What properties is a characteristic of the simple organic compounds in general A ionic B high melting points boiling points C soluble in water D inflammable?
D
How do you differentiate simple molecular compounds and giant molecular compounds?
simple molecular compounds have weak forces of atraction.
