Covalent bond (molecular bond): a chemical bond that involves the sharing of electron pairs between atoms.
1. Non-polar covalent bond: the electrons are shared equally between atoms
ex: CH₄ (methane)
2. Polar covalent bond: the electrons are not shared equality between atoms
ex: H₂O (water)
Ionic bond: a chemical bond formed between two ions with opposite charges
ex: NaCl (sodium chloride)
To know the difference between ionic and covalent bonding, one must first understand the chemical difference between sharing electrons and being attracted by charges to one another.
Every atom wants to fulfill the octet rule, or, getting to a stable 8 electrons in its outermost shell. (Having 8 valence electrons)
Atoms in covalent bonds do this by sharing electrons. A good analogy to express this would be if there was a toy that we both wanted, but there was only one of them. Instead of you or I having it to ourselves, we would share. This is what atoms in covalent bonds do.
Atoms in ionic bonds do this by transferring electrons. Sodium loses an electron and chlorine gains an electron (becoming chloride). This is like you taking the toy to yourself. Now because sodium is now a positive ion and chloride is a negative ion, the two come together because opposite charges attract.
I really hope this helps!
Best wishes!:)
Answer:
<em>No, these exceptions do not discredit natural selection.</em>
Explanation:
Natural selection tends to favour those organisms which are better adapted to live in an environment. But it does not completely remove the other organisms from the world that are less adapted to live in an environment. Usually, the number of these organisms that are not favoured by natural selection is very less as compared to the number of organisms which are favoured by natural selection. As we see, the number of albino animals is far lesser as compared to their wild-type animals.
Answer:
Human activities are causing imbalance of carbon based molecule.
Explanation:
It is the human intervention in the most unavoidable way that is affecting the environmental cycle and one of these cycle is the carbon cycle. Human activities such as burning of fossil fuels, excessive cutting of trees, rising green house effect, use of CFCs etc is hindering the environment process and hence causing imbalance on the earth.
Answer:
Explanation:
Telomeres are distinctive structures found at the ends of our chromosomes. They consist of the same short DNA sequence repeated over and over again. Telomeres are sections of DNA? found at the ends of each of our chromosomes?. They consist of the same sequence of bases ?repeated over and over.
