Atoms And Elements Flashcards
What is an Atom?
The smallest identifiable unit of an element.
Daltons Atomic Theory.
- Each element is composed of tiny indestructible particles called atoms
- All atoms of a given element have the same mass and other properties that distinguish them from the atoms of other elements
- Atoms combine in simple. Whole number ratios to form compounds.
What is an Electron?
A negatively charged particle that occupies most of the atoms volume but contributes almost none of its mass.
What is in an atoms nucleus?
The atoms nucleus contains both positively charged protons and neutral particles called neutrons.
What is atomic number?
The number of protons in the nucleus of an atom.
What is periodic law?
When elements are arranged in order of increasing relative mass, certain sets of properties recur periodically.
Where on the periodic table are metals located?
What are some properties of metals?
The left side of the periodic table.
- good conductors of heat and electricity
- can be pounded into flat sheets ( malleability)
- can be drawn into wires (ductile)
- are often shiny
- tend to lose electrons
Where on the periodic table are Nonmetals located?
What are properties of nonmetals?
The upper right side of the periodic table.
- have varied properties ( solids, or gases at room temp)
- poor conductors of heat and electricity
- gain electrons when undergoing a chemical reaction.
Where are metalloids located on the periodic table?
Along the zig - zag diagonal line dividing metals and non metals.
Nobel Gasses
Group 8A, are chemical inert gases.
Alkali Metals
Group 1A, reactive metals
Alkaline Earth Metals
Group 2A, fairly reactive but not as reactive as Alkali Metals
Halogens
Group 7A, very reactive nonmetals
Ion Charge
Number of protons - number of electron
What are cations
Positively charged ions
