Chemistry Partial Jan. Flashcards
What are major elements?
Elements found in almost all of Earth’s living systems, often in relatively large quantities.
What are Biogenic Elements?
Chemical elements constantly present in organisms and having definite biological significance.
Name the 6 major elements
Carbon, Hydrogen, Oxygen, Nitrogen, Sulfur, Phosphorus
What are minor elements?
Elements found in many of Earth’s living systems, and/or in relatively small quantities.
Name the 5 minor elements
Sodium, Potassium, Magnesium, Calcium, Chlorine
What are trace elements?
Essential elements necessary only in very small quantities to maintain the chemical reactions on which life depends, or elements found only a very few of Earth’s living systems.
Name all the trace elements?
Manganese, Iron, Cobalt, Copper, Zinc, Boron, Aluminum, Vanadium, Molybdenum, Iodine, Silicon, Nickel, Bromine
Define Chemical bond
Force that hold two atoms together in a compound.
Define Valence electrons
Electrons present in the last level of an atom.
Who described the term of electronegativity?
Linus Carl Pauling
Define Electronegativity
The ability/capacity to attract electrons.
The greater the difference in electronegativity between tow atoms…
The easiest the electron transfer.
What is Polarity?
It depends in the difference between electronegativity values of each atom.
Similar electronegativities = …
Low polarity
Different electronegativities = …
High polarity
How do you know if a chemical bond is a Non polar Covalent?
If its difference in electronegativity is from 0-0.3
How do you know if a chemical bond is a Polar Covalent?
If its difference in electronegativity is from 0.4-1.7
How do you know if a chemical bond is Ionic.
If its difference in electronegativity is greater or equal than 1.8
The weakest type of bond…
Non Polar Covalent
The strongest type of bond…
Ionic
What is a molecular orbital?
A mathematical function describing the wave-like behavior of an electron in a molecule
What is a bond length?
The average distance between nuclei of two bonded atoms in a molecule
What is bond energy?
The measure of bond strength in a chemical bond
What is a covalent bond?
A chemical bond that involves the sharing of electron pairs between atoms.
what is a non polar covalent bond?
Bonding between non-metals, consists of two electrons shared between two atoms.
what is a polar covalent?
Bond between two non-metals with different electronegativities.
If Bond strength increases…
Bond energy increases
If Bond strength decreases…
Bond energy decreases
