Question | Answer |
Matter | material that has mass and occupies space |
Pure Substance | matter that has a fixed or definite composition 1.) elements or 2. compounds |
Element | A pure substance that cannot be separated into any simpler substances by chemical methods |
Compounds | 1. Pure substances 2. consist of a combination of two or more elements 3. always in same ratio Ex. H2O is water - but H2O2 is hydrogen peroxide |
Mixture | Two or more substances are physically mixed, but not chemically combined |
Homogeneous mixture | 1. Also called solution 2. Air & salt water are examples 3. Composition is uniform throughout sample |
Heterogeneous mixture | Components are NOT uniform throughout sample Ex. choc. chip cookies; oil & water |
Na - What is Latin root? | Natrium = salt = sodium |
Fe - Latin root | Ferrum = Iron |
Ag - Latin root | Argentum = silver |
Who invented Periodic Table? | Mendeleev |
Period - describe | A horizontal row on the Periodic Table 2. each has a number (regular print) |
Group - how designated on Periodic Table? | Each VERTICAL COLUMN contains a group or family of elements with similar properties 3. Designated 1A - (sometimes with Roman numerals) |
Alkali metals | Group 1A elements 2. Soft, shiny metals 3. Good conductors of heat 4. Relatively low melting points 5. React with water |
Is hydrogen alkali metal? | No, even though it is at top of Column 1A |
Alkali metals (names) | LI - Lithium, Na - sodium, K - potassium, RB rubidium, Cs Cesium |
Al | (blank) |
Alkaline Earth metals (properties) | Shiny metals, but not as reactive as Group 1A |
Halogens - Group 7A (17) | Strongly reactive-form compounds |
Halogens - name some elements | F-fluorine, Cl-chlorine, Br-bromine, I- iodine and At astatine |
Zigzag line on periodic table | Separates Metals from nonmetals |
Metalloids | Located adjacent to the zigzag line |
Atom | smallest particle of an element that retains the characteristics of that element |
Dalton's Atomic Theory (4) | a. All matter is made of tiny particles-atoms 2. Atoms of one element are different from others 3. Atoms combine to form compounds 4. Chemical reactions combines atoms; but they are never created or destroyed--rearrangements |
Proton | subatomic particle with a POSITIVE charge |
Electron | subatomic particle with NEGATIVe Charge |
amu | Atomic Mass Unit - Defined as 1/12 the mass of the carbon atom |
Rutherford's experiment | Gold foil was bombarded with positive particles - who deflected paths rather than pass straight through - the NUCLEUS surrounded by mostly empty space |
Atomic number | Equals # of PROTONS in element |
Mass number | Mass number = number of protons plus number of neutrons |
Isotopes | Atoms of the same element with a different number of NEUTRONS Ex. Mg - can be Mg24/12 Mg 25/12 or Mg 26/12 |
How can you tell it is an isotope? | Write Atomic Symbol with mass number on top, element in middle, atomic number on bottom |
Atomic mass-how do you determine? | AVERAGE of weights of all isotopes of the element |
Calculate Atomic Mass | Multiply isotope by its mass times its "abundance" (percent found) = average atom |
Atomic spectrum | Each element creates unique pattern of colors when light emitted from a heated element is passed through a prism |
Quantized | Refers to different energy levels in atomic pathways |
Sublevels | Energy levels within atoms; contain electrons with identical energy |
Orbital | Region//pathway where electron is likely to be found |
Pauli exclusion principle | States that any given orbital can hold up to 2 electrons but no more |
Orbital diagram | Electron configurations/pathways |
Electron configuration | Patterns of energy within the structure of the atoms |
alkali | A (first group) includes Li (lithium) K Potassium and Na (sodium) |
alkaline earh metals | Begins with Be (Berium) Mg (magnesium) Calcium (Ca) |
Halogens | F (flourine) Cl (chlorine) Br (bromine) react quick as HAL-ogens |
isotope | Atoms with different numbers of neutrons (DOUBLE O's in isotope mean double neutrons) |
How can you tell it's an isotope? | Look at mass number - written top right "isolated" from regular atoms |
How referred? | Magnesium-24, Magnesium-25, Magnesium 26 |
copper Cu is in what part of periodic table? | transition elements |