Answer:
"The elements are arranged in seven horizontal rows,called periods or series,and 18 vertical columns,called Groups."
Explanation:
Risk*
Answer:
the lighter fresh water rises up and over the salt water
Explanation:
this is because the salt water is denser
Lava I think try that hope it helps :)
Answer:- A. 
is not the correct formula.
Explanations:- Charge for Ba is +2 and charge for O is -2, Here the charges are in equal and opposite so their ratio is 1:1 and hence the formula must be BaO and not .
Rest of the formulas are correct as charge for Ca is +2 and charge for N is -3 . On criss cross we get the formula 
.
Charge for K is +1 and charge for Cl is -1 and so KCl is correct.
Charge for Li is +1 and that for S is -2. On criss cross we get the formula 
.
Answer:
4.549 kg.
Explanation:
- We can use the general law of ideal gas: <em>PV = nRT.</em>
where, P is the pressure of the gas in atm (P = 2 x 10⁴ kPa/101.325 = 197.4 atm).
V is the volume of the gas in L (V = 20.0 L).
n is the no. of moles of the gas in mol (n = ??? mol).
R is the general gas constant (R = 0.0821 L.atm/mol.K),
T is the temperature of the gas in K (T = 23° C + 273 = 296 K).
<em>∴ n = PV/RT =</em> (197.4 atm)(20.0 L)/(0.0821 L.atm/mol.K)(296 K) = <em>162.5 mol.</em>
- To find the mass of N₂ in the cylinder, we can use the relation:
<em>mass of N₂ = (no. of moles of N₂)*(molar mass of N₂) = </em>(162.5 mol)*(28.0 g/mol) = <em>4549 g = 4.549 kg.</em>
