Chapter 2 Flashcards
what is an element ?
the simplest type of substance with unique physical and chemical properties. An element consists of only one type of atom
what is a molecule ?
a structure that consists of two or more atoms that are bound together and thus behaves as an independent unit. atoms may or may not be the same
what is a compound ?
a substance composed of two or more different elements which are chemically combined. it may or may not involve sharing electrons between the atoms
what is a mixture ?
a group of two or more elements and/or compounds that are chemically or physically intermingled
mass analysis of Na3P shows that it contains 23.0g of sodium and 10.3 g of phosphorus. How many mg of sodium are in 144.9mg of Na3P?
100mg Na
what charge is a proton ?
1 +
what charge is a neutron?
0
what charge is an electron ?
1-
where is the proton located ?
nucleus
where is the neutron located ?
nucleus
where is the electron located ?
outside the nucleus
copper has two natural occurring isotopes, 63Cu (isotope mass = 62.9396) and 65Cu (isotopic mass = 64.9278 amu). if copper has an atomic mass of 63.546 amu, what is the percent abundance of each isotope?
63Cu: 69.50 percent
65Cu: 20.50 percent
what’s the monoatomic ion of iodine?
iodide , I-
what is the monoatomic ion formed by calcium?
Ca^2+
what is the monoatomic ion formed by aluminum?
Al^3+
when do covalent bonds form ?
when non metals bind to non metals
what are examples of a diatomic molecule ?
H2, N2, O2, F2, Cl2, Br2, I2
are there molecules in an ionic compound ?
no
are molecules present in a sample of BaF2?
no , because Ba is a metal and F is a non metal
are ions present in a sample of P4O6?
no because they are sharing electrons. each of them are non metals
what is the formula for Na+Cl-
NaCl
what is the formula for Mg2+ Cl-
MgCl2
what do calcium and bromine form ?
calcium bromide (CaBr2)
