Week 2 Chemistry Flashcards
What is matter?
anything that takes up space and has a mass
What are atoms?
Smallest unit of matter known as an atom.
What are the three states of matter?
Solids, Liquids, Gasses
What is the relationship between atoms and hot and cold?
Atoms are always moving (vibrating). The movement of an atom is what we refer to as heat.
How do atoms form solids?
Atoms link together into molecules using covalent bonds. These bonds are formed because almost no loose atoms have the amount of electrons they prefer to have around them
What is the structure of atoms?
A single atom is composed of a central nucleus surrounded by clouds of electrons
What are protons?
Protons give atoms their identity. They are +ively charged
What do the number of protons determine?
It’s atomic number & what element it is. + charge
What is the atomic number of an element ?
The number of protons that are present in an atom
What are neurons?
No charge but help keep the nucleus together. Neutral. (sub-atomic particle in the nucleus)
What is the mass number of an element?
The sum of protons and neutrons in the nucleus
What is an isotope?
Contain the same number of protons but different number of neurons. (not all cases)
What is the atomic mass of an element?
It equals the number of protons and neutrons within the nucleolus (p+n) = atomic mass
What are electrons?
A subatomic particle (can have both mass and no mass)
The number of electrons is always equal to the number of protons found in an element - charge
How was electrons arranged around the nucleus
First shell (2 electrons) Second shell (max 8 electrons) Valence shell 8 electrons. :(octet rule)
What are three categories of pure substances?
Elements, molecules, compounds
What is an element?
Usually refers to a substance made up of one type of atom and the properties of that substance
Describe a molecule
Is a substance made up of two or more atoms which are either from the same element or different element that form a unit
Describe a compound
A substance made up of two or more atoms which form different elements
Describe metabolism
The chemical processes that occur within a living organisms in order to maintain life
Define Catabolisim
The break down of complex molecules
Define Anabolism
systhesis of complex molecules (build up)
What are electron shells?
Holds electrons 2:8:8 octet rule
What is the outer most shell that contains electrons called?
Valence shell (third shell)
What element category needs full electron shells?
Nobel gases, 8 in the vallance shell
What is a mixture?
2 or more elements that are physically combined together. But are not bound by chemical bonds.
What can mixtures contain?
Solids, liquids and gasses, either alone or in combination
What is a solvent?
Liquid (or gas) in which another substance is dissolved to form a solution
How does water act as a solvent?
H2o is charged, it disrupts the bonds resulting in individual molecules floating around.
What are colloids?
A mixture of solute and solvent. The particles are large enough to scatter light as it passes through
What are suspensions?
A mixture of particles in a liquid for a period of time, will eventually settle out of liquid
What is a mole?
It’s a measurement chemist use
What is concerntration?
The number of molecules present in a given volume. Can be described in %
What is the definition of molarity?
Molecules in a reaction, measuring them in relation to weight to express the concentration of a chemical
What is the formula of the mole?
atomic number + atomic number = molecular weights.
(Actual weight) - provided in question.
Actual weight / molecular weight = X
X/Litres = Mole
What are the types of chemical bonds?
Ionic bonds
Covalent bonds
Metallic bonds
Hydrogen bonds
What is an Ionic Bond?
is the complete transfer of valence electron(s) between atoms. Valence shell of 7 electrons
What is an Covalent Bonds
They’re not physically exchanged. They share electrons to fill there valance shell.
Describe Non-Polar Covalent Bonds
Equal sharing of electrons so the resulting molecule has no charge associated with it.
Describe Polar Covalent Bonds
The sharing of the electrons is uneven.
Describe Metallic bonds
Metals tend to have a few extra electrons in there valence shells.
Describe Hydrogen Bonding
Weaker interactions that alter the way molecules interact with eachother.
What are the two components to a chemical reaction?
The reactant
The product
What is a chemical reaction?
The bonds that hold atoms together are broken and rearranged to make new substances.
What is energy?
The capacity for doing work or causing change.
Energy comes from two forms, what are they?
Potential energy
Kinetic energy
What is potential energy?
Energy stored by matter due to it’s position
What is kinetic energy?
Energy associated with matter in motion
What is chemical energy?
Form of potentislal energy that is stored in chemical bonds. (endothermix and exothermic)
Describe exothermic
An exothermic reaction is a chemical reaction that releases energy through light or heat
Describe endothermic
Endothermic process is any process which requires or absorbs energy from its surroundings, usually in the form of heat
What are different types of reactions?
Synthesis
Decomposition
Exchange
Reversible
Describe Synthesis reaction
Two or more atoms/molecules are bonded together to form a more complex molecule
Describe Decomposition reaction
A larger molecules broken apart into simpler substances
Describe Exchange reaction
What one atom/functional group replaces another in a compound. Both synthesis and decomposition
Describe Reversible reaction
A reaction that can proceed in both direction
What is activation energy
A type of reaction to get bonds between atoms to form or break, a collision with enough energy is required.
Describe catalysts
Is a chemical substance that acts to lower the activation energy required for certain chemical reaction
Catalysis is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst,
What is an enzyme?
An enzyme is a protein that acts as a catalyst
How do enzymes work?
Attracts reactants binding them at the active site, working on them, producing the products then releasing the products. Lock & key
