1 / 47

MLT 1101 CHEMISTRY

MLT 1101 CHEMISTRY. TOPIC 1 MATTER AND THE THEORY OF STATE MATTER. INTRODUCTION TO THE MATTER. Matter is anything that occupies space and has mass . Matter can classified into physical and chemical state. There are 4 physical states of matter : 1) Gas or Vapor

faolan
Télécharger la présentation

MLT 1101 CHEMISTRY

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. MLT 1101CHEMISTRY TOPIC 1 MATTER AND THE THEORY OF STATE MATTER

  2. INTRODUCTION TO THE MATTER

  3. Matter is anything that occupies space and has mass. • Matter can classified into physical and chemical state. • There are 4 physical states of matter : 1) Gasor Vapor • No fixed volume or shape - it conforms to the container. • Can be compressed or expanded • Move randomly at great speeds • Can vibrate, rotate, translate & have highest energy content

  4. 2) Liquid • Has a fixed volume - shape depends on its container. • Cannot compressed. • Particle can vibrate, rotate & translate. 3) Solid • Has a fixed shape and volume; it is rigid • Cannot compressed. • Particles can vibrate & rotate at fixed positions 4) Plasma • is a substance similar to gas in which electrically neutral medium of positive and negative particles • they generate electrical currents by charges.

  5. THEORYOF STATE MATTER • Matter is made up of tiny and discrete particles. There are spaces between these particles. • The particles may be atoms, molecules or ions. • An atom is the smallest particle of an element that can participate in a chemical reaction. • A molecules is a group of two or more atoms which are chemically bonded together. • An ion is a positively-charged or negatively-charged particle.

  6. Particles of Matter are constantly moving & contain kinetic energy. • Particles of Matter are held together by very strong electric forces • Matter can be classified by its chemical constituent whch are elements and compounds. a) An elements is a substance that consists of only one type of atom. b) A compound is a substance that contains two or more elements that are chemically bonded together.

  7. 5. Each substance has unique particles that are different from the particles of other substances 6. Temperature affects the speed of the particles.  The higher the temperature, the faster the speed of the particles.

  8. CLASSIFICATION OF MATTER

  9. States of Matter

  10. Matter changes

  11. Sublimation Boiling/ evaporation Melting Freezing Condensation LIQUID SOLID GAS Sublimation Heat energy absorbed Heat energy released

  12. Heating curve Melting point – Temperature at which it changes from solid to liquid state Boiling point – Temperature at which it changes from liquid to gas state.

  13. During Heating… • When a solid is heated, the particles absorb heat energy. • The particles vibrate faster and kinetic energy increase. • The movement of particles is increase • The force of attraction become weak

  14. Cooling curve Freezing point – Temperature at which it changes from liquid to solid state Condensation point – Temperature at which it changes from gas to liquid state

  15. During Cooling… • When a gas is cooled, the particles release the energy. • The kinetic energy will decrease • The movement of particles is decrease • The force of attraction become strong

  16. PHYSICAL AND CHEMICAL CHANGES PHYSICAL CHANGES CHEMICAL CHANGES • A change that alters the APPEARANCE of a material but does not make the material into another substance • Physical changes are REVERSIBLE • Examples: tearing paper, chopping wood, molding clay, melting ice • a change in matter that PRODUCES A NEW SUBSTANCE • Signs that a chemical change has taken place: • bubbles appear • precipitate forms • color change • light is emitted • temperature change • change in smell or taste • Energy is ALWAYS involved during BOTH physical and chemical changes

  17. Subatomic particles of an atom • Atoms are made up of three types of smaller particles, namely protons, neutrons and electrons. These particles are known as subatomic particles. • The relative masses and charges of these three subatomic particles in table below.

  18. Subatomic particles of an atom • Protons and neutrons are found in the nucleus of an atom while electrons surround the nucleus.

  19. SYMBOLS OF ELEMENTS • Each element is given a name and a symbol. Some examples of elements and their symbols are shown below.

  20. Notice that: • Each symbols consists of one or two letters. • For most elements, the letters used in their symbols take either the first letter or first and another letter of their names. Eg. Hydrogen, H; neon, Ne and Magnesium, Mg. • For some elements, the symbols come from Latin names such as natrium (Na) for sodium and kalium (K) for potassium.

  21. B 11 5 Proton number = 5 Nucleon number = 11 Neutron number = 11 – 5 = 6 Nucleon number A x Symbol of element Proton number Z

  22. PROTON NUMBER & NUCLEON NUMBER • Proton number : an elements is the number of protons in its atom. • Since atoms are neutral, the proton number is also the number of electrons in the atom. • Each elements has its own proton number. • E.g: • sodium has a proton number of 11. Hence all atoms of sodium have 11 protons. • Oxygen has a proton number of 8, so all oxygen atoms have 8 protons.

  23. The nucleon number is also known as the mass number. • The relative mass of an atom is almost the same as its nucleon number. The nucleon number is sometimes used as the approximate relative mass in calculations. • Protons and neutrons are collectively called nucleons because protons and neutrons occupy the nucleus.

  24. Nucleon number: total number of protons and total number of neutrons in its atom. • From definition, or Nucleon number = number of proton + number of neutrons Number of neutrons = nucleon number – number of proton

  25. Remember the charge on each subatomic particle like this: Protons are positive, Neutrons are neutral, so electrons must be negative. • In a neutral atom, number of electrons = number of protons

  26. ISOTOPES • Isotopes are atoms of the same element with the same number of protons but different numbers of neutrons.

  27. Isotopes of an element have the same: (a) number of protons in an atom. (b) number of electrons in an atom. (c) electron arrangement. (d) chemical properties because they have the same electron arrangement.

  28. Isotopes of an element have different: (a) nucleon number. (b) number of neutrons in an atom. (c) physical properties (such as density, melting point and boiling point), though these different are very small.

  29. USES OF ISOTOPES • There are 2 types of isotopes, namely the radioactive and the non-radioactive isotopes. • Radioactive isotopes or radioisotopes produce harmful radiation. • However, radioisotopes can have important uses if they are handled properly. They are used in medicine, industry, agriculture and general research.

  30. 1) Medical use • Gamma-rays emitted from cobalt-60 are used in radiotherapy for the treatment of cancer. • Superficial cancers such as skin cancer can be treated by less penetrating radiation from phosphorus-32 or strontium-90. • A heart pacemaker which contains plutonium-238 is used to regulate the heartbeats of patients with heart problems. • Iodine-131 is used in the treatment of thyroid diseases.

  31. 2) Agricultural uses • The uptake of phosphate and the metabolism of phosphorus by plants can be studied using a phosphate fertiliser containing phosphorus-32. • Radioactive tracer studies using carbon-14 have helped in the understanding of photosynthesis and protein synthesis.

  32. 3) Industry uses • Sodium-24 can be used to trace leaks in gas or oil pipes and ventilating systems. • The gamma rays of cobalt-60 are passed through food to destroy bacteria which cause the food to spoil without changing the quality, flavour, or texture of the food. • The radiation from krypton-85 can be used to control the thickness of plastic sheets in the industry.

  33. 4) Power sources • Uranium-235 is the most common fuel used in nuclear power stations. 5) Archaeological uses • Carbon-14 can be used to estimate the age bone, wood or fossils by measuring the fraction of carbon-14 it contains.

  34. ELECTRONIC STRUCTURE OF AN ATOM • Electrons are arranged around the nucleus in the shells of an atom. • The shell of an atom are numbered 1, 2, 3 and so on, starting from the one closest to the nucleus. • Each shell can occupy a certain number of electron.

  35. ELECTRONIC STRUCTURE OF AN ATOM First shell : 2 electrons 3 2 Second shell: 8 electrons 1 Third shell: 8 electrons + Fourth shell: 18 electrons nucleus

  36. FINDING THE ELECTRON ARRANGEMENT • To write the electron arrangement of an atom, follow these steps: STEPS 1 – Find out the proton number of the atom. (can refer to the Periodic Table) STEPS 2 – Find out the number of electrons of the atom. For a neutral atom, the number of electrons is the same as the number of protons.

  37. FINDING THE ELECTRON ARRANGEMENT • STEPS 3 – Arrange the electrons in shells. Electrons occupy the shell closest to the nucleus first. The electrons only start occupying a new shell when the previous one has been occupied.

  38. VALENCE ELECTRONS • Valence electrons are found in the outermost occupied shell of an atom. • They determine the chemical properties of the element

  39. VALENCE ELECTRONS • For e.g: the electron arrangement of a chlorine atom is 2.8.7. There are 7 electrons in the outermost occupied shell of the chlorine atom. Therefore, the number of valence electrons in a chlorine atom is 7.

  40. Thank You

  41. Quiz!!

  42. 1) How many states of matter are there? A) 1 B)2 C) 3 D)4 ANS: There are 4 states of matter. You will find solids, liquids, gases and plasmas. 2) Atoms in a liquid are farther apart than the atoms in a gas. A) true B) false ANS: Atoms in a gas are actually farther apart than the atoms in a liquid. Solids are the densest state of matter (of solids liquids, and gases). Gases are the least dense and have atoms that are the most spread out.

  43. 3) Which has the least energetic molecules?a) Solids b) Liquids c) Gases d) Plasmas Ans : Solids have the least energetic molecules. Plasmas and gases have the most energetic atoms. 4) What force pulls liquids towards the ground?a) Pressure b) Temperature c) Gravity d) centrifugal Ans: Gravity is the one force that pulls every object towards the surface of the Earth.

  44. When a substance goes from being a solid to a liquid, it is a...a) chemical change b) Physical change Ans: When a substance moves from one state to another, it is a physical change. Physical changes usually happen because you add or take away energy. If one substance combines with another to make a new compound... That is a chemical change.

  45. Study smart!!!

More Related