Answer:
There are 5 neutrons in beryllium
<h2><u>
Answer:</u></h2>
0.126 Liters
<h2><u>
Explanation:</u></h2>
V = mRT / mmP
First, convert the 2.25g of Nitrogen gas into moles. (m in the equation above)
2.25g x 1 mole / 28.0g = 0.08036 moles = m
28.0g = mm
Next, convert the 273 Celsius into Kelvin. (T in the equation above)
273 Celsius + 273.15 = 546.15K = T
R = 0.08206L*atm/mol*K
(Quick Note: The R changes depending on the Pressure Unit so do not use this number every time.)
Now, plug everything into the equation.
V = (0.08036)(0.08206)(546.15)/(28.0)(1.02)
V = 0.126 L
Answer is: MgF₂, magnesium fluoride.
Magnesium fluoride is salt, ionic compound, because magnesium is metal from 2. group of Periodic table of elements and has low ionisation energy and electronegativity, which means it easily lose valence electons, fluorine is nonmetal with greatest electronegativity, which meand it easily gain electron, so magnesium cation (Mg²⁺) and fluorine anion (F⁻) are formed.
The formula is m = D x V
D = <span>13.69 g/cm^3.
</span>V = <span>15.0 cm^3
the mass of the liquid mercury is m= </span>13.69 g/cm^3 x 15.0 cm^3 = 195g
the molar mass of Hg is 200,
1 mole of Hg = 200g Hg, so #mole of Hg= 195 / 200 = 0.97 mol
but we know that
1 mole = 6.022 E23 atoms
0.97 mole=?
6.022 E23 atoms x 0.97 / 1 mole = 5.84 E23 atoms
Elements of Group 1 and group 2 in the periodic
table contain elements so reactive that they are never found in the free state
<u>Explanation</u>:
The metals in group 1 of periodic table consisting of 'alkali metals' which include lithium, potassium, sodium, rubidium, Francium and caesium. They are highly reactive because they have low ionisation energy and larger radius. The group 2 metals consist of 'alkaline earth metals' which include calcium, strontium, barium, beryllium, radium and magnesium. These alkaline earth metal have +2 oxidation number, hence are highly reactive.
These both group metals are mostly reactive and so are never found in a free state. When they are exposed to air they would immediately react with oxygen. Hence, are stored in oils to avoid oxidation.
