LIFE ON MARS The Chemistry of Life

What does matter look like on the most basic level? Atom – From the Greek word atomos, which means “unable to be cut”; Very small in size smallest particle of matter Cannot be broken down any smaller Made up of protons, neutrons and electrons

Atomic Structure The atomic nucleus is located at the center of the atom and is made of: Subatomic Particles Proton (+) positively charged Neutron (0) no charge Electrons Move around the nucleus in energy levels (-) negatively charged and smallest Electrons are in constant motion outside the nucleus

Sketch an Atom

http://htwins.net/scale2/ How small is an atom?

Most of the atom is empty space If the atom was the size of this classroom, the nucleus would be the size of a grain of sand in the middle!!

Elements – An element is a pure substance made of one type of atom More than 100 are known Only about 24 are commonly found in organisms ATOMIC NUMBER = # or protons Ex. Carbon has 6 protons, so it has an atomic number of 6 Examples: Oxygen Hydrogen, and Carbon Mass number= the sum of the protons and neutrons Ex. Carbon has 6 protons and 6 neutrons; the mass number of carbon is 12

I made the PERIODIC TABLE ! I am Dmitri Mendeleev! I made the PERIODIC TABLE !

What is the PERIODIC TABLE? Shows all known elements in the universe. Organizes the elements by chemical properties.

How do you read the PERIODIC TABLE?

Elements are represented by a 1 or 2-letter symbol (see p. 1086) Elements are represented by a 1 or 2-letter symbol (see p.1086). Be familiar with the following elements: C = carbon O = oxygen H = hydrogen

What is the ATOMIC NUMBER? The number of protons found in the nucleus of an atom Or The number of electrons surrounding the nucleus of an atom.

What is the SYMBOL? An abbreviation of the element name.

What is the ATOMIC WEIGHT? The number of protons and neutrons in the nucleus of an atom.

How do I find the number of protons, electrons, and neutrons in an element using the periodic table? # of PROTONS = ATOMIC NUMBER # of ELECTRONS = ATOMIC NUMBER # of NEUTRONS = ATOMIC _ ATOMIC WEIGHT NUMBER

What is an ELEMENT? A substance composed of a single kind of atom. Cannot be broken down into another substance by chemical or physical means.

What is a COMPOUND? A substance in which two or more different elements are CHEMICALLY bonded together.

Examples: H2O is made of 2 Hydrogen atoms and 1 oxygen; NaCl is made of 1 Sodium and 1 chlorine atom 2. The chemical properties of a compound are different from the elements that form the compound

What is a MIXTURE? Two or more substances that are mixed together but are NOT chemically bonded.

Element, Compound or Mixture?

a. solutions – when all components are evenly spread in water Two types of mixtures: a. solutions – when all components are evenly spread in water solute - substance that is dissolved solvent – the substance that dissolves the solute (ex: water) b. suspensions – when all components are not completely dissolved in water

Element, Compound or Mixture?

Element, Compound or Mixture?

Element, Compound or Mixture?

Element, Compound or Mixture?

Element Composition of… Earth Mars Oxygen 47% Silicon 27% Aluminum 8% Iron 5% Calcium 4% Oxygen Silicon Iron Magnesium  Aluminum  Calcium