The Chemistry Of Life Flashcards
(23 cards)
What are the four elements that make up 96% of most living organisms
Carbon
Hydrogen
Oxygen
Nitrogen
What are the components of atoms and their charges?
Proton (positively charged)
Neutron (neutrally charged)
Electrons (negatively charged)
What is a proton
A proton is a subatomic particle with one unit of positive charge found in the nucleus.
Protons equals to you atomic number
What is your atomic mass/mass number?
Indicates how much protons and neutrons are in the nucleus and gives an approximate of how much matter that atom contains.
What is your atomic mass expressed in?
The units are:
amu - atomic mass unit
Daltons
Explain the term isotopes
Are elements that have the same atomic number, but differ in its number of neutrons.
Same atomic number but different mass number.
What are radioisotopes?
Some isotopes that have excess neutrons tend to become and unstable and break down(decay). When they decay the emit radiation thus the reason why they are called radioisotopes.
Note: many radioisotopes are important to research and medicine.
What are orbitals?
Orbitals are regions of 3D space and these are what electrons occupy.
The energy on these orbitals depend and how close or far the are from the nucleus.
Closer-less energy
Further-more energy
What are valence electrons?
They are your outermost electrons.
What are your most unreactive elements?
Noble gases
What are the different ways to represent chemical formulas?
Empirical formula - simplest formula
Molecular formula
Structural formula
What are chemical bonds and give examples
Are forces of attraction between atoms
Examples: covalent, ionic and hydrogen bonds
What occurs in a covalent bond?
In covalent bonding electrons are shared in order to fill their valence shells. Eg. hydrogen
Covalent bonds a strong chemical bonds.
What types of covalent bonds can exist?
Single
Double
Triple
What is electronegative?
The degree at which an element tends to gain electrons and form ions. The more protons are in a nucleus the electrons are able to be attracted.
What is a non-polar covalent bond?
This bond forms when electrons are shared equally.
Eg. O2, Co2 and H2
What are polar covalent bonds?
Forms when one atom is more electronegative than the other(creates a positive and negative ends)
H2O
What are ionic bonds?
Forms between cations (positively charged looses electrons) and anions(negatively charged gains electrons).
Atoms become ions when the gain or loose electrons to become stable.
Types of cations
Looses one electrons
Hydrogen
Sodium
Potassium
Losses two electrons
Calcium
Magnesium
Ferrous
What are hydrogen bonds
Are weak attractions involving partially charges hydrogen atoms but a strong collectively.
What are the properties of water?
Polar
Easily dissociates
Universal solvent
High specific heat
High heat of vaporization
Important in metabolism lubricant
Supporting substance
Explain high heat capacity as it relates to water
High specific heat capacity
Heat capacity is the amount of heat energy required to raise the temperature of a substance by one degree. Because water has a high specific heat capacity it takes a great amount of heat to raise it kinetic energy. This helps to stabilize the earth’s temperature. (When water is being warmed up it absorbs the heat of the atmosphere thus allows it to become cooler when water is being cooled it release energy (heat) thus warming up the atmosphere) This has to do with the covalent bond between the two hydrogen atoms because covalent bonds are strong it requires a lot of energy to break those bounds which allows the water particles to move.
Water heats up slowly and cools down slowly(when water cools down the hydrogen bonds re-form)
Explain the dissociation as it relates to water
water has the tendency to be ionized into hydroxyl ions OH negative and hydronium ions H positive.
This accounts for how acidic or basic(alkaline) a substance is. This is where the ph scale comes into play. The higher concentration of H plus ions there are the more acidic a substance is said to be.
pH greater than 7 is alkaline more
hydroxyl ions
Bases are protons acceptors, has a low concentration of H plus ions and releases hydroxyl ions in solution.
pH lower than 7 is acidic a more hydrogen ions
Acids are protons donors, has a large concentration of hydrogen ions and releases hydronium ions in solutions.
Neutral substances are when H = OH
