Chemical Principles Flashcards
(91 cards)
Atom
Smallest unit of matter which can partake in a chemical reaction
Smallest unit of matter which can partake in a chemical reaction is the
Atom
Element
Composed of one type of atom
Example of an element
Carbon, Nitrogen and Oxygen
Composed of one type of atom
element
Molecule is formed when
When 2 or more atoms join together
- the atoms can be the same or difference
- Same: N2O2
- Different: H2O
2 or more atoms joined together forms a
molecule
- atoms can be the same or be difference
Explain the atomic structure
Every atom is composed of a single centrally located nucleus which contains protons (carrying a positive charge) and neutrons (which carry no charge)
- since neutrons carry no charge, the nucleus will always carry a net positive charge
- nuclear contents do not participate in chemical reactions and thus is referred to as stable
Electrons exist outside of the nucleus is specialized regions of space called orbitals and they carry a negative charge
What is the nucleus composed of
Protons (positive charge) and Neutrons (no charge) = net positive charge
What part of the atomic structure does not participate in chemical reactions and is referred to as stable
The nucleus
What charge does the nucleus have
A net positive charge (b/c the neutrons have no charges and protons have a positive charge)
What are orbitals
specialized regions of space that exist outside of the nucleus, and electrons are in these orbitals
- carry a negative charge
ions
when an atom has an overall positive or negative charge - it is no longer netural and is referred to as an ion
- an atom that looses an electron will have a net positive charge
- When an atom gains an electron it will have a net negative charge
Cation
atoms carrying a positive charge
Anion
Atoms carrying a negative charge
Na has an atomic # of 11 and Cl has an atomic # of 17 what will happen?
an ionic bond
Na^+ and Cl^- ionic bond
Chemical bonds form…?
Why do chemical bonds exist?
What are the types of chemical bonds
- form in between atoms when electrons in their outer shells interact with one another
- every atom wants to achieve chemical stability & they do this by filling their outermost shell w/ electrons
- Atoms achieve a full complement of electrons (8) by combining to form molecules - Three types of chemical bonds found in living systems
covalent, ionic and hydrogen bonds
three types of chemical bonds
Covalent, Ionic and Hydrogen bonds
Covalent bonds
very strong bonds
- formed when two atoms come together and share electrons within their outershell
- Water is formed as a result of covalent bonds in between hydrogen and oxygen
Ionic bonds
These bonds form as a result of the attractive force in betwen ions of opposite charge
- weaker than covalent
- The attractive force holds the two atoms together in the bond
ex) NaCl
- Na requires the loss of an electron to achieve stability and CL requires the gain of an electron to achieve stability
- Cl recieves the electrons from Na rather than sharing it : Cl
- Cl becomes Cl^- and Na becomes Na^+
Hydrogen Bonds
Are also covalent bonds
These bonds form when Hydrogen is covalently bound to oxygen or another electron loving molecule such as nitrogen
*- i.e N and O are electron loving - greedy for electrons *
Since the atom bound to hydrogen is “electron loving” it holds the shared electrons closer to its nucleus than hydrogen
Explain the hydrogen bonds between
H : C and
H : O
H and C
- Non- polar covalent bond
- carbon is not more electron loving than hydrogen, thus the electrons are equally shared in between the two atoms
H and O
- polar covalent bond
- Oxygen is more electron loving than hydrogen, thus the electrons are not equally shared in between the two atoms and are held more closely to the Oxygens nucleus
- Oxygen gets a partial negative charge and hydrogen gets a partial positive charge
Explain partial positive and negative charges between atoms and Polar/non-polar molecules
they happen when there unequal sharing of electrons between two atoms resulting in Partial positive charge and a
Partial negative charge
Molecules that contain unequal sharing of electrons are polar molecules, vice versa equal sharing of electrons are non-polar molecules
Explain water with polar covalent bonds and hydrogen bonds
Water has a partial negative on the O atom, and a partial positive charge on the 2 H atoms, resulting in a polar covalent bond due to unequal sharing of electrons (electrons held closely to O)
Since theres partial + and - charges, the partial + charge on the hydrogen atom is attracted to partial - charge on atoms within another molecule = hydrogen Bond
- hydrogen bonds are weaker than both covalent and ionic - heat breaks down these hydrogen bonds
-Hydrogen bonds result in networks of molecules of different molecules