what is a half life
how long it takes for half of the element to decay
what is a chemical bond
force that holds two or more atoms together
true or false matter can be destroyed
false
true or false the mole number is 6.022x1023
true
0.5 mole O2 + ____ moles H2O
2H2 + O2 --> 2H2O
1 mole
what is the 16th element of the periodic table
sulfur
true or false an ionic bond is formed by a metal and nonmetal
true
what are the three states of matter
gas, liquid, solid
what is the molar mass of NH3 to the nearest hundredth
17.03g/mole
3.5 mole H2 = ____ g H2O
2H2 + O2 --> 2H2O
63.07g
what is the most reactive element
francium
what is a covalent Bond
electrons are shared by the nuclei of both atoms
what is the fourth state of matter
plasma
what is the name of 6.022x1023
Avogadros number
nitrogen gas reacts with hydrogen gas to produce ammonia, NH3. what mass of ammonia is produced when 6.50 moles of nitrogen reacts with hydrogen
222 grams of NH3
what is the most dangerous type of nuclear decay
gamma radiation
a polar covalent bond is when
the atoms are not shared equally
how old is the earth
4.5 billion years old
convert 6.9 x 1025 molecules to moles
114.58 moles
how many grams of KCl are needed to make 500ml of a 1 M solution
37.3g KCl
what is nuclear fission
when 2 nuclei join together to form a larger nucleus
how many valence electrons are in radon
8
convert 26.4 miles to km
42.5 km
if you had a mole of pennies how deep would the earth be covered in meters
300 meters
what is the percent yield if 500g of sulfur trioxide react with an excess of water to produce 575g of sulfuric acid
SO3 + H2O--> H2SO4
94%