Chemistry Flashcards
What is a polar molecule
A neutral, or uncharged molecule that has an asymmetric internal distribution of charge leading to partially positive and partially negative regions
What is cohesion
The attraction of molecules for other molecules of the same kind
What is adhesion
The attraction of molecules for other molecules of a different kind
Define “Homeostasis”
The Maintenance of stable conditions inside of the body.
What is an Atom
The basic unit of a chemical element. It consists of subatomic particles such as PROTONS, NEUTRONS and ELECTRONS.
What 3 parts does an atom consist of?
Protons, Neutrons and Electrons
What is contained in the nucleus of an atom?
Protons and Neutrons
Where would you find an Electron?
Electrons can be found within an atom surrounding a nucleus in a cloud or shell
Define proton
A proton is a large, positively charged particle
What does the number of protons in the nucleus determine?
What the element is
Define Neutron
A neutron is housed in the nucleus and contains a neutral charge.
A neutron determines isotopes
Define electron
An electron is a very small negatively charged particle which is housed around the nucleus in a shell or cloud.
What is the “The Octet Rule”?
Electrons in the Valance Shell always want to be paired in order to be stable.
When not paired the atom will want to give up or gain one electron so that it can have a full outer/valence shell and be stable.
What is the outter most shell of an atom called?
The Valance Shell
What can you tell me about the inner-most shell of the carbon atom?
The carbon atom will have only 2 atoms within its innermost shell, as is the case with all elements
What is the number at the top of an element within the periodic table?
The Atomic Number and this represents the number of protons in the nucleus.
What does the atomic number represent?
The number of protons in the nucleus
Where will you find the “Mass Number” in the periodic table?
Below each element, this will be the the sum of protons added to the number of neutrons within an atom.
What is the “Mass Number”?
The mass number is the sum of protons (+) added with the number of neutrons (=) within an atom
What is an “Isotope”
An isotope is an atom with the same number of protons (+) but a different number of neutrons (=)
What is unusual about an Isotope?
The element can have differing numbers of neutrons (=) but always has the same number of protons (+) in the nucleus.
When the number of neutrons (=) is different, the mass number is also different.
What are the 4 main elements that make up our mass?
Oxygen, Carbon, Hydrogen and Nitrogen in descending order of abundance
What is the MOST common element in our make up?
OXYGEN
Lesser elements making up the 3.6%
Calcium, Phosphorus, Potassium, Sulphur, Sodium, Chlorine, Magnesium and Iron
What is common about each column group in the periodic table?
They have matching valence electrons in their outter shell
What are the electrons called in the outter most shell of the atom?
Valence Electrons
What is common about atoms with similar valence electrons?
They will have similar reactivity and form similar ions
What is an ION?
An ion is an atom or molecule that has that has given up or gained an electron in its valence shell. It will be negatively or positively charged due to the unequal amount of protons and electrons.
What are the two types of ions?
Cations - given AWAY electron(s) and POSITIVELY charged
Anions - GAINED electron(s) and NEGATIVELY charged
What is a Cation
An atom or molecule that has given away electrons, POSITIVELY charged.
What is an Anion?
An atom or molecule which has gained or stolen electrons. It is NEGATIVELY charged.
Examples of Cations
Atoms which have lost or given away electrons may be Hydrogen, Lithium and Sodium
Examples of Anions
Atoms which have taken or gained electrons may be Fluorine and Chlorine.
Also being negatively charged.
What holds out bones and teeth together?
Ionic Bonds
What do ionic bonds primarily do?
Give away, or take full electrons so that one element may become positively charge and the other, which is gaining electrons, would become negative
What are electrolytes?
Ions such as Sodium, Potassium and Calcium.
These are necessary for nerve impulse conduction, muscle contractions and water balance!
Why are electrolytes important?
They are necessary for nerve impulse conduction, muscle contractions and water balance
What is an example of an ionic bond?
NaCl
Sodium Chloride
What is true of Covalent Bonds?
They SHARE electrons, and are more common that ionic bonds within the molecules of living organisms.
Generally the strongest.
What is a polar covalent bond?
When the sharing of electrons is UNEQUAL and there is partial charge distribution of the molecules
What is a non-polar bond?
When the bond has equal electrons to be shared and the electronegative values are even.
(Wants to give electrons as much as wants to gain electrons)
What are the 2 types of covalent bonds?
Polar (unequal electronegativity)
Non-Polar (equal electronegative)
What are polar covalent bonds?
Bonds with electrons that are unequally shared by the atoms and spend more time by one atom than the other.
Due to this unequal distribution of electrons between the atoms of different elements, partially positive/negative charges develop in parts of the molecule.
What is a non-polar covalent bond?
Between 2 atoms of the same element or, that share electrons more or less equally
Hydrogen Bonds
Polar covalent bond with a slight positive charges attracting to neighbouring negative charges.
These are common, and water molecules in particular form lots of them.
Individually they are week and easily broken, but together can be very strong.
What is a chemical bond?
A force that holds atoms of a molecule or compound together