UPCAT CHEMISTRY

• is anything that occupies space and has mass.

  Matter
• f that property can be measured without changing the chemical composition of that matter, it is a

  physical property
• re those that depend on the amount of matter being measured. The classic examples of extensive physical properties are the mass, volume, and number of moles. Decreasing the amount of matter being weighed will definitely decrease the mass of that matter.


  extensive properties
• are independent of the amount of matter being considered. Classic examples of intensive properties are color, melting point, boiling point, and density. The density of water, regardless of whether you use 1 mL or 1 L of it, will be the same at a certain temperature.

  intensive properties
• describe the characteristic ability of a substance to react to form new substances

  chemical properties
• is a form of matter that has a definite composition and distinct properties

  substance
• A substance that cannot be broken down into simpler substances using any chemical means is known as an

  element
• When two or more types of elements are used in fixed proportion with one another to form a single substance, a

  compound
• is a combination of two or more substances in which the substances retain their distinct identities.

  mixture
• he composition of the mixture is the same all throughout. In other words, if you cannot recognize the individual components of a mixture, then it is

  homogenous mixture
• The component that exists in the greatest amount is the

  solvent
• s/are the component/s that exist in minor amount/s.


  solute
• can be further subdivided into suspension and colloids.

  heterogenous
• When a beam of light is passed through a colloid, the dispersed phase scatters it. This phenomenon is known as the


  tyndall effect
• is the basic unit of an element that can enter into a chemical combination

  atom
• are negatively charge subparticles


  electrons
• Proposed that matter is composed of indivisible particles called 'atomos'


  democritus
• : Formulated modern atomic theory, stating:

  • All matter is made of atoms, indivisible and indestructible (later disproven by discovery of subatomic particles).
  • Atoms of a given element are identical in mass and properties.
  • Atoms combine in fixed ratios to form compounds.
  • Chemical reactions rearrange atoms but do not change them.


  john dalton
• Revealed that atoms have a dense, positively charged nucleus, leading to the nuclear model of the atom.

  Rutherford's gold foil experiment
• • discovered neutrons, explaining the mass difference in elements like hydrogen and helium.


  james chadwick
• discovered electrons and proposed the "plum pudding model" where electrons are embedded in a positive sphere.


  J.J Thomson
• Number of protons in the nucleus, determines the element.

  Atomic Number
• Sum of protons and neutrons.

  Mass number
• Atoms of the same element with different numbers of neutrons.


  isotopes
• Electrons orbit the nucleus in fixed orbits (later modified).


  Bohrs model
• • Electrons exist in probability clouds called orbitals.


  quantum mechanical model
• Indicates the energy level and size of the orbital.


  principal quantum number
• Defines the shape of the orbital (s, p, d, f).

  azimuthal quantum number
• Specifies the orientation of the orbital.

  magnetic quantum number
• Describes the spin of the electron (+½ or -½).

  spin quantum number
• Electrons fill the lowest energy orbitals first.


  aufbau principle
• No two electrons can have the same set of quantum numbers.

  Pauli Exclusion Principle
• Electrons occupy orbitals singly before pairing up.

  Hund's Rule
• no electric charge


  neutron
• postive charge


  proton
• Elements in groups 1, 2, and 3-17 are called the

  representative elements or main group elements
• group 1 is known as the

  alkali metals
• Group 2, on the other hand, is known as

  alkaline earth metals
• Together with the alkali metals, groups 1 and 2 (except H and Be) form strong inorganic bases when bonded with hydroxide ions. Furthermore, these two groups are sometimes referred to as the


  s block elements
• Group 18,have completely filled p subshells (except He). Aside from helium, all members of the group have 8 electrons in their valence shell.


  noble gases