Problem 1
The text (from the screenshot you posted) mentions that
"The atoms of covalent materials are bound tightly to each other in stable molecules, but those molecules are generally not very strongly attracted to other molecules in the material"
Put another way, we can think of each atom as a person, and each molecule as a family or a collection of persons. This is because any molecule is a collection of atoms. In covalent molecules, the connection between any two families isn't that strong since each person is focused more on their respective family, instead of other people outside the family. This is one way to think of it, but you may have a more effective way to remember.
In short, the exterior bonds between different covalent molecules isn't that strong, which means it's easier to break those bonds.
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Problem 2
The text also says
"The atoms (ions) in ionic materials show strong attractions to other ions in their vicinity"
This is due to the positively and negatively charged ions that attract to one another, and this causes a stronger chain so to speak. The stronger the chain, the harder it is to break when you apply temperature to it. Keep in mind that the only difference between a solid and a liquid is that the solid is a rigid structure while a liquid is more loose and free flowing. The ionic materials having a stronger inner bond like this is why ionic materials have higher melting points. You need to apply more temperature than normal to get the solid to melt.
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Problem 3
Again we turn to the text and it says
"For example, the molecule carbon tetrachloride is a non-polar covalent molecule, CCl4. It's melting point is -23 degrees Celsius. By contrast, the ionic solid NaCl has a melting point of 800 degrees Celsius"
In short, the difference between the two is that carbon tetrachloride has covalent bonds and NaCl (sodium chloride, aka table salt) has ionic bonds. It's much easier to melt the carbon tetrachloride than it is to melt the table salt.
Side note: carbon tetrachloride was historically used in fire extinguishers, but have been phased out due to safety concerns. Exposure to this toxin can lead to central nervous system problems, kidney failure, or liver problems. Due to its very low melting point, carbon tetrachloride is a liquid at STP.
1. Covalent compounds are held together by weak intermolecular forces. It is because of such weaker forces, which fails to make the compound bind tightly. Since lower heat (energy) is capable of breaking these weak intermolecular forces, therefore the melting and boiling points of covalent compounds is low.
2. Ionic compounds are held together by electrostatic forces between the oppositely charged ions . As the ionic lattice contains such a large number of ions, a lot of energy is needed to overcome this ionic bonding so ionic compounds have high melting and boiling points.
3. In terms of chemical bonding, carbon tetrachloride is a covalent chemical compound whereas sodium chloride is an ionic chemical compound. NaCl is solid in nature while CCl₄ is liquid.
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brainly.com/question/3447218
2. Which property is a property of water? (Choose all that apply
Cohesion
Relatively high boiling point
High surface tension
Adhesion
Answer:
cohesion and adhesion
Answer:
Cohesion, Adhesion, Relatively high boiling point, and high surface tension.
Explanation:
Cohesion and adhesion give water molecules their 'stickiness' for each other and other molecules/surfaces, and high surface tension is why things like feathers can 'float' on the surface of water.
All of the following have an OCTET of electrons except
о
S-1
O
N-3
O
Be+2
O
Br-1
Answer:
full octets live in noble gas world so you need to be whatever your charge is away from there in steps on the periodic table so s-1 is the one that falls short as it is 2 moves away from Ar which is its closest Noble gas
Explanation:
Help me plzz it’s for
Why is the average air temperature of Makassar warmer than the average air
temperature of Chirstchurch?
Answer:
becuase of the sun
in different places some places would be cold
Which instrument is used to take an image from outer space that shows the depletion of the ozone layer in Earth’s atmosphere?
Answer:
answer is satellite!
Explanation:
similarities between mole and MOL
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Answer:
Explanation:
In all, an estimated 8,000 to 10,000 Iraqi forces were killed, in comparison with only 300 coalition troops. Though the Gulf War was recognized as a decisive victory for the coalition, Kuwait and Iraq suffered enormous damage, and Saddam Hussein was not forced from power.
hope this helps a lot!