Chemistry, chapter 3
Terms
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- Chemical reaction
- The transformation of a substance or substances into one or more new substances
- Law of conservation of mass
- Mass is neither created nor destroyed during ordinary chemical reactions or physical changes.
- Law of definite proportions
- A chemical contains the same elements in exactly the same proportions by mass regardless of the size of the sample or source of the compound
- Law of multiple properties
- If two or more different compounds are composed of the same two, then the ratio of the masses of the second element combined with a certain mass of the first element is always a ratio of small whole numbers
- Daltons atomic theory
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1- All matter is composed or extremely small particles called atoms
2- Atoms of a given element are identical in size, mass, and other properties; atoms of different elements differ in size, mass and other properties
3- Atoms cannot be subdivided, created, or destroyed
4- Atoms of different element combine in simple whole-number ratios to form chemical compounds
5-In chemical reactions, atoms are combined, seperated, or rearranged - Scientific theory
- theory that can be tested by experiments
- Modern atomic theory
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1-All matter is composed of atoms
2-Atoms of any one element differ in properties from atoms of another element remain unchanged. - Atom
- the smallest particle of an element that still retains the chemical properties of that element
- nucleus
- the very small region located at the center of the atom
- Proton
- Positively charged particle located in the nucleus
- neutrons
- Neutrally charged particle located in the nucleus
- Electrons
- Negatively charged particles which surround the nucleus
- Subatomic particals
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-Protons
-neutrons
-electrons - cathode ray tubes
- Glass tubes which carried out experiments
- nuclear forces
- These short-range proton-neutron,proton-proton, and nuetron-neutron forces hold the nuclear particles together
- Atomic number
- The...of an element is the number of protons of each atom of that element
- Isotopes
- Atoms of the same element that have different masses
- Hydrogen isotopes
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-protium
-deuterium
-tritium - Mass number
- The .... is the total number of protons and neutrons that make up the nucleus of an isotope.
- Nuclide
- ....general term for a specific isotope of an element
- Atomic mass unit (amu)
- 1 amu is exactly 1/12 the mass of a carbon-12 atom
- Average atomic mass
- The weighted average of the atomic masses of the naturally occuring isotopes of an element
- Mole (mol)
- The amount of a substance that contains as many particles as there are atoms in exactly 12 grams of carbon-12
- Avogadro's number
- 6.022x10^23- the number if particles in exactly one mole of a pure substance
- molar mass
- The mass of one mole of a pure substance
- Mass to Moles (conversion)
- 1 mol/molar mass of element
- Moles to mass (conversion)
- Molar mass of element/ 1 mol
- Moles to atoms (conversion)
- 6.022x 10^23 atoms/1 mol
- Atoms to moles (conversions)
- 1 mol/ 6.022 x 10^23