Atomic Structure & Mixtures, Compounds, Elements

Size of the Atom ► Average sized atom cm ► Aluminum foil 50,000 atoms thick ► 1 penny 20,000,000,000,000,000,000,000 atoms of copper and zinc (20 thousand billion billion

Parts of the Atom ► Proton- Positive (+) particle (nucleus) ► Determines the element ► Neutron- Neutral (0)particle (nucleus) ► Nucleus- Central, dense core of atom  Protons and neutrons are found in the nucleus of the atom and make up almost all the mass of the atom. ► Electron- Negative (-) particle (electron cloud around nucleus)

Modern view of the atom ► The atom is mostly empty space ► Nucleus – Protons and neutrons ► Electron cloud is the area where electrons of an atom are most likely found.

Counting the Pieces Review ► Atomic Number= Number of protons ► Atomic Mass= Protons + Neutrons ► # of protons determines kind of atom. ► Neutral Atom= the same number of protons and electrons ► All particles in the atom have mass. ► Proton= 1amu (atomic mass unit) ► Neutron= 1amu ► Electrons have a very small mass

Atoms and Elements ► Atoms of different elements are different  Determined by # of protons ► Atoms of the same element are almost the same  Isotopes have a different number of neutrons  Does not change the charge of the atom.  Occur naturally and share the same properties  Some are unstable and the nucleus can change composition (radioactive isotopes)

Isotope

Naming the Isotopes ► 3 2 He ► 4 2 He ► 12 6 C ► 14 6 C ► U ► U Mass number of this atom Atomic number of the element This atom of hydrogen has two protons and one neutron = 3 amu Atomic Mass Atomic Number Element Symbol

Write the isotopes of Hydrogen shown. 11H11H 21H21H 31H31H

Atomic Mass ► The atomic mass is not a whole number because it is a weighted average of all the oxygen isotopes in the world.

Measuring Atomic Mass ► Atomic mass is measured in Atomic Mass Units or AMU’s and is the addition of the number of Protons and Neutrons in an atom. Same number of electrons & Protons Neutrons different. Atomic Mass=________

Measuring Atomic Mass ► An AMU is 1/12 the mass of a carbon 12 atom. ► Each isotope has a unique atomic mass. The atomic mass listed on the Periodic table is an average of all the atoms in the world.

Element ► An element is a pure substance that cannot be broken down into simpler substances and have the same properties ► Classified by properties ► Grouped into categories using these properties ► Metals ► Metalloids ► Non-metals

Element

Types of elements on the P.T. List the qualities/location ► Metals  Two types ► Metals on the right ____________________________________________ ► Metals on the left ____________________________________________

Element Listed on the P.T. of E. organized into three categories.. Metal

Types of elements on the P.T. List the qualities/location ► Metals ► Metalloids  _______________________________________

Element Listed on the P.T. of E. organized into three categories.. Metal Metalloid

Types of elements on the P.T. List the qualities/location ► Metals ► Metalloids ► Non-metals  _______________________________________

Element Listed on the P.T. of E. organized into three categories.. Metal Non- Metal Metalloid

Element Listed on the P.T. of E. organized into three categories.. Metal Non- Metal Metalloid Combine to form Mixture

Mixture ► Combinations of 2 or more chemical substances (elements or compounds) that can easily be separated back into their original compounds. ► Mixtures can be liquids or gasses

Mixtures

Element Listed on the P.T. of E. organized into three categories.. Metal Non- Metal Metalloid Combine to form Mixture SolutionSuspensionColloid

Solution ► Mixture that appears as a single substance

Solution

Element Listed on the P.T. of E. organized into three categories.. Metal Non- Metal Metalloid Combine to form Mixture SolutionSuspensionColloid SolventSolute

Solvent ► In a solution the solvent makes up most of the mixture. ► It dissolves the solvent. In this photo… What is the solvent.

Solute ► The solute is the substance being dissolved in the solute. In this photo… What is the solute.

Solute enters system. Time Passes. Solute spreads out evenly.

Suspension ► Mixture that has particles dispersed through out that are large enough to settle out over time.

Suspension

Colloids ► Mixture that has particles dispersed through out that are not large enough to settle out over time.

Colloids

Element Listed on the P.T. of E. organized into three categories.. Metal Non- Metal Metalloid Combine to form Mixture SolutionSuspensionColloid SolventSolute Compounds

Compound ► Any combination of 2 or more elements that can only be separated by chemical means.

Compounds

Difference between Elements & Compounds

Review Which box contains ► a) one element ► b) a mixture of elements ► c) a pure compound ► d) a mixture of elements and a compound? What might be happening in this box?

Review Fill in this chart…. ► The protons and neutrons are found in the…………….. of the atom, called the nucleus. ► The zoom around the nucleus in shells. The 1st shell, which is the nucleus, can hold.... electrons, whereas the 2nd and 3rd shells can hold electrons.

Review a) What is the atomic number of an atom? The number of protons in an atom. b) What is the atomic mass of an atom? The protons plus the neutrons. c) What is the atomic number of the atom below? What is its atomic mass? Atomic mass Atomic number

Review Give the numbers of protons, electrons & neutrons a) 14 7 N b) Ne c) 19 9 F d) K e) Co f) U ProtonsNeutronsElectrons A) B) C) D) E) F)

Review