<span>2.70x10^7 pm^3
We will assume that the sodium atom closely approximates a sphere. So the expression for the volume of a sphere is
V = 4/3 pi r^3
V = 4/3 pi (186 pm)^3
V = 4/3 pi 6434856 pm^3
V = 26954261.78 pm^3
Round to 3 significant figures, giving 2.70x10^7 pm^3</span>
Answer:
399
Explanation:
Pb(SO4)2 contains 1 atom of Pb, 2 atoms of S and 8 atoms of O. So, atomic mass of Pb(SO4)2 is 207 + 64 + 128 = 399 u. Therefore, molar mass of Pb(SO4)2 is 399 g/mol.HOPE THIS helps. Good Luck
Answer 1
The sample will dissolve in more than 1 minute.
Explanation :-
Generally Solubility and rate of solubility of substances increase with the increase in temperature. So lower the temperature less fast will it dissolve in the same amount of water.
Since at 50 C it takes 1 minute to dissolve, at 20 C which is lower temperature it will take more time to dissolve.
Answer 2
Transition metals
Explanation:-
Hardness depends on the extent of metallic bonding for metals. More the number of electrons more the metallic bonding.
Alkali metals with just 1 valence electron have weak metallic bonding. Alkaline earth metals have just 2 valence electrons. Transition elements has more electrons in penultimate shell and valence shell than lanthanides. Transition metals with most metallic bonding are the hardest
Answer:
58.32
Explanation:
The mass number is one mole and for Mg it is 24.306 for O it is 15.999 and for H it is 1.008. because O and H have 2, you multiply them by 2 and add all the numbers and it equals 58.32
Answer:
A crack in earth's crust is called a fault also known as a "fracture"