Viewing All Flashcards for Chapter 2: Atoms & the Periodic Table
Questions
Answers
1)
- The smallest quantity of matter that still retains the properties of matter
2)
- a substance that cannot be broken down into 2 or more simpler substances by any means Ex: Gold, oxygen, helium
3)
- matter composed of particles- particles called "atomos" (uncuttable)
-1799- Law of definite proportions
5)
-1803- Atomic Theory: a precise definition of the atom
- different samples of a pure chemical substance always contain the SAME PROPORTION OF ELEMENTS by massEx: water always contains 8 g oxygen per 1 gram of hydrogen
- elements are composed of small particles called ATOMS- all atoms of a given element are IDENTICAL (have same size, mass, and chemical properties)- the atoms of one element are DIFFERENT from atoms of all other elements-COMPOUNDS are composed of atoms of more than one element
- REARRANGEMENT- atoms are NOT destroyed or created in chemical reactions
- even smaller particles which give atoms their internal structure (and properties) ~electrons, protons, neutrons
10)
-the emission and transmission of energy in the form of waves
-1895- Rontgen, Bequerel, & M. Curie
- electrons- cathode ray tube experiment
Robert Millikan- oil-drop experiment
- nuclear model- scattering of alpha particles
-James Chadwick- nuclear transformations
16)
- positively charged particles (deflected away from positively charged plate)
17)
- negatively charged particles (deflected away from negatively charged plate)
18)
-high energy EM radiation- have no charge and are unaffected by external electric or magnetic fields
9.10 * 10^-28 g
ELECTRONS
21)
Atomic number = number of protons in the nucleus- defines the element- equal to the number of electrons in the atom- determines position in the periodic table
22)
A = total number of protons & neutrons in the nucleusA = Z + (# neutrons)# n's = A-ZA = mass of the atom in amu
23)
- different forms of the same element- the 2 forms have the same # p & e, but DIFFERENT # neutrons-have the same Z but different A- they have the same chemical properties (because properties are determined primarily by # of electrons and protons in the atoms
- average mass
- periodic table
26)
- a chart in which elements have similar chemical and physical properties are grouped together
- arranged by increasing atomic number (Z)
HORIZONTAL rows numbered 1-7
VERTICAL columns containing elements of SIMILAR CHEMICAL PROPERTIES
30)
- the mass of an INDIVIDUAL MOLECULE in atomic mass units (amu)- the SUM of the atomic masses that make up the molecule
31)
1 mol = 6.022 * 10^23 = Avogadro's number = NsubscriptA
32)
The molar mass (M) of anything (molecules, eggs, etc.) is the MASS OF 1 MOLE of that thing in grams.molar mass (g) = molecular mass (amu)
= n (Nsubscript A)