Answer: Heterogenous mixtures are the ones in which we can see the different components clearly. Air is considered to be homogenous, because we don't see the different noble gases' particles floating around. Salt water is also homogenous, because salt dissolves almost completely into water, becoming hard to see without the proper equipment salt particles in it. Steel is also homogenous, since the metals that compose it are mixed during the heating. The only heterogenous would be soil, because we can see different particles in it, with different sizes, shapes, colors, etc without having to use special equipment.
Answer:
0.104 M
Explanation:
<em>A saline solution contains 0.770 g of NaCl (molar mass = 58.55 g/mol) in 133 mL.</em>
<em />
The molar mass of the solute (NaCl) is 58.55 g/mol. The moles corresponding to 0.770 g are:
0.770 g × (1 mol/55.85 g) = 0.0138 mol
The volume of solution is 133 mL. In liters,
133 mL × (1 L/1000 mL) = 0.133 L
The molarity of NaCl is:
M = moles of solute / liters of solution
M = 0.0138 mol / 0.133 L
M = 0.104 M
A major factor in how the periodic table<span> is organized is the configuration of each </span>element's<span> valence electrons. Because </span>elements<span> in each family have the same number of valence electrons, they tend to have several similar </span>characteristics<span>.</span>
Answer:
28.11g
Explanation:
Step 1:
Background understanding:
From Avogadro's hypothesis, 1 mole of any substance contains 6.02x10^23 atoms. This also indicates that 1 mole of helium (He) contains 6.02x10^23 atoms.
1 mole of He = 4g
Step 2:
Determination of the mass of He that contain 4.23x10^24 atoms. This is illustrated below:
4g of He contains 6.02x10^23 atoms.
Therefore Xg of He will contain 4.23x10^24 atoms i.e
Xg of He = (4x4.23x10^24)/6.02x10^23
Xg of He = 28.11g
Therefore, 28.11g of He contains 4.23x10^24 atoms
