1 / 12

120 likes | 287 Views

Physical Science Moles. Atomic number- number of protons in that atom Represented by “Z” Ex) Z=11 Mass number- number of protons and neutrons Represented by “A” Ex) A=19. Calculating # of neutrons. Mass number (A) : - Atomic number (Z): ______________________ Number of neutrons:.

Download Presentation
## Physical Science Moles

**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

**Atomic number- number of protons in that atom**• Represented by “Z” • Ex) Z=11 • Mass number- number of protons and neutrons • Represented by “A” • Ex) A=19**Calculating # of neutrons**Mass number (A) : - Atomic number (Z): ______________________ Number of neutrons:**Average atomic mass**• An element’s average atomic mass is a weighted average of the masses of its naturally occurring isotopes. • Unit : amu**Properties of Metals**• Shiny, malleable, ductile, good conductors of heat and electricity • Alkali metals-react violently with water • (very reactive b/c has 1 valence electron Na+) • Alkaline earth metals- • (reactive usually 2 valence electrons Mg 2+) • Transition metals- not as reactive Au, Ag will form cations (ex. Au 3+ ) • Semiconductor can conduct under certain conditions**Properties of Nonmetals**• All except for hydrogen are found on the right side of the periodic table. • Can be solids, liquids, gases • solids are usually dull, brittle and poor conductors of electricity and heat.**Nonmetals**• Halogens – very reactive, generally accept electrons Cl- , F-, I- • Noble Gases- exist as single atoms instead of molecules. Generally do not react because s and p orbitals are full. • Ex) Ne, Ar, He**Moles**• Return to the metric system!!! • Mole-abbreviated mol • A collection of a very large number of particles about • 602 213 670 000 000 000 000 000=??? • Avagadro’s constant- the number of particles in 1 mol of a pure substance**Why 6.022x10 23 ?**• The mole is defined as the number of atoms in 12.00 g of carbon-12. • Experiments show that 6.022x10 23 is the number of carbon-12 atoms in 12.00g of carbon-12 • One mole of carbon consists of 6.022x10 23 carbon atoms with an average atomic mass of 12.01 amu**Molar mass**• The mass in grams of 1 mol of a substance. • 1 mol of carbon-12 atoms has a molar mass of 12.00g. • But a mole of an element will usually include atoms of several isotopes. • So the molar mass of an element is the same as its average atomic mass in amu. • Carbon is 12.01amu, one mole of carbon has a mass of 12.01g**Conversion factors**• A ratio derived from the equality of two different units and that can be used to convert from one unit to another Amount (mol)Mass g amount (mol)x molar mass of element 1 mol of element Mass g Amount (mol)**Examples**• What is the mass of 5.50 mol of iron? • Using periodic table, find iron • Average atomic mass = amu • So molar mass = g/mol Fe • Now, set up problem 5.50mol Fe x 55.85 g Fe = 307 g Fe 1 mol Fe

More Related