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38 Cards in this Set
- Front
- Back
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What is matter
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anything that takes up space and has mass
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Matter is made of?
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Elements
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What's an element
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substance which cannot be broken down into other substances by chemical reactions
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How many elements are there
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92, all have distinct characteristics as both singluar elements and when combined with others
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What's a compound
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substance which consists of elements in a set ratio
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How many essential elements
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25 -- necessary for life, biological functions
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96% of living matter is made up of these four essential elements
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O (oxygen), C (carbon), H (hydrogen), N (nitrogen)
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4% of living matter is made of these elements
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Ca, P, K, S, Na, Cl, Mg
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Essential Elements required in tiny amounts
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Trace elements
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Element deficiency affects proper functioning? T / F
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True
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What are atoms
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Smallest unit of matter which still retains elemental properties
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Atoms are made up of
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Subatomic particals
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What are the three subatomic particals that make up an atom?
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proton, neutron, electron
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Mass or weight of subatomical particals measured in
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Daltons
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Most atomic mass of an element is made up of these subatomic particals
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Protons and neutrons
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atomic nucleus is made up of
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- protons + neutrons
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What surrounds nucleus
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Electron cloud
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what holds the atom together
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opposing charges
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atoms are made up of mostly empty space
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true
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Atomic number is?
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# of protons, unique to the element
subscript to left of elemental symbol |
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What's the mass number
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# of protons and neutrons together
superscript to the left of the element |
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What's atomic mass?
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total mass of atom, in daltons
generally very close to mass number superscript |
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What are isotopes
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atomic forms of a given element, each with a different # of neutrons (and different atomic mass)
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radioactive isotope
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unstable, degrades and releases particles and energy
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what can we do with isotopes
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used as tools, like carbon dating and tracers
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What is energy
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the capacity to cause change, especially to do work
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what's potential energy
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energy due to location or structure, matter naturally moves to the lowest possible state of PE - ball at the top of the hill
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Electron energy
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further an electron is from nucleus, the higher its potential energy, due to opposing charges - rubber band illustration
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Electron shell
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location of a given electron
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Electron Shell Placement
1st shell 2nd shell 3rd shell |
closest to nucleus max 2 e-
8 e- 18 e- |
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High electron shell =
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higher potential energy (PE)
farther away from the nucleus - higher the PE |
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What's the valence shell?
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outermost electron shell
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How do atoms interact
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though electron shells
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"Valence e-" also means?
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in valence shell
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Atomic behavior depends on what?
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# of e- in the valence shell
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What are the two characteristics of inert elements?
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full valence shell
chemically un-reactive |
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What is the identifying characteristic of a chemically reactive element?
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they have an incomplete valence shell
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What is an orbital?
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the 3-D space where an e- is located 90% of the time
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