Chemistry of Biology Flashcards
What is “matter”?
Anything occupies space and mass
What is an atom?
The smallest unit of matter. Building blocks of matter
What is the anatomy of an atom?
Neutron (nucleus), proton (positive charge), electron (negative charge)
What is an atomic number?
Number of protons in the atom.
What is the similarity between the electrons and protons in the atomic mass?
Same number of electrons and protons
What is the anatomy of an atom card.
Atomic number at left corner
Element symbol in the middle
Element name under
Atomic mass middle bottom
What are the different types of chemical bonds? (3)
Covalent bond, ionic bond and hydrogen bond
Describe a covalent bond.
The covalent bond needs to be stable, all of its shells need to be filled. There is 2 types of covalent bond: non-poplar and polar.
What is the different between non-polar and polar covalent bond?
Non-polar: attracted by equal forces
Polar bond: Unequal pull between atoms creating small charges. The bond has an unbalanced atomic mass which leads to this unequal pull. The electrons don’t have the same charges, therefore together, the electrons are complete.
Describe and give examples of an ionic bond.
During an ionic bond, the electrons jump to one another. When it gains or lose electrons, it then becomes an ion. It has a pretty strong bond but not as much as the covalent bond. An example would be sodium (Na+) bonded with chlorine (Cl) (NaCl).
Describe a hydrogen bond.
This is a weak bond formed by the attraction between polar molecules that can be broken up easily with heat. It is when a slightly positive hydrogen atom is attracted to a slightly negative atom such as F, O, N. This is the interaction between molecules when H is already bonded with F, O or N. Therefore H+Cl with another molecule could not form a hydrogen bond. F, O or N attract more electrons and become slightly negative while H become slightly positive.
What are the properties of water? (4)
Cohesion, surface tension
Large heat capacity
Low density as a solid
Good solvent
Describe what is cohesion in the properties of water.
This is when the hydrogen bon makes the water molecule “stick together”, therefore it shrinks, takes up less space. It then gives water a surface tension with a net-like properties. Water molecules easily form hydrogen bonds giving great cohesiveness giving the chance to insects to walk on water.
Describe what is high heat capacity in the properties of water.
Since hydrogen bonds are a weak bond, the heat from the sun does not increase the water temperature, it only rearranges their bonds by doing and undoing bonds between each others. It requires more heat than other elements to heat up. It also conserves heat in colder temperature which is why it takes more time for water to release the heat.
Describe what is low density as a solid in the properties of water.
Water ha a lower density when frozen which explains why the ice floats on water. The ice and snow acts as insulation for the water below which is why fishes can survive underneath the ice. It is like insolation.
