True because if an old theory finds new information that can be changed if it’s different then the original material
There are a number of
ways to express concentration of a solution. This includes molarity. Molarity
is expressed as the number of moles of solute per volume of the solution. The
concentration of the solution is calculated as follows:
<span> </span><span>Molarity = 15.5 g NaOH (1 mol NaOH / 40 g NaOH) / .250 L
solution</span>
<span>Molarity = 1.55 M</span>
Answer:
0.0025moles
Explanation:
Molarity of a solution (M) = number of moles (n) ÷ volume (V)
According to this question, to make 250 mL of a 0.01 M solution of CaCl, the following number of moles is needed:
Volume = 250mL = 250/1000 = 0.250Litres.
Using; molarity = n/V
0.01 = n/0.250
n = 0.0025
n = 2.5 × 10^-3 moles.
Answer:
A. Metalloid
E. Has similar properties as Ge
F. Belongs to Period 3
Explanation:
Silicon is the 14th element on the periodic table. Its unit is SI. Its properties straddles between those of metals and non-metals and it is described as a non-metal.
It's atomic weight or mass number is 28u. It has an atomic number of 14 i.e in its neutral state, the number of protons and electrons are equal to 14.
Silicon belongs to the 4th group and the 3rd period on the periodic table. Elements in the same group share similar chemical properties. The elements in Si group are: C, Ge, Sn and Pb. The properties of Si is similar to these elements because they all have a valency of 4. Across the period, the properties varies this is why Si would have a very different property from Al and P.
