<h3><u>Answer;</u></h3>
As, & Sr --------[Kr]
Be ------------------- [He]
O, & Mg ----------[Ne]
S, & Ca -------------[Ar]
<h3><u>Explanation</u></h3>
- <u>The Be+ ion has 2 electrons, just like He. The ions Mg2+ and O2− each has 10 electrons like Ne. </u>
- <u>The S2− and Ca2+ each has 18 electrons like Ar. The ions As3− and Sr+ each have 36 electrons like Kr.</u>
- <u>Atoms of elements lose or gain electrons to attain a stable configuration which is equivalent to the configuration of noble gases.</u>
- When atoms lose or gain electrons they form ions, which are either positively charged or negatively charged. When atoms lose electrons they form positively charged ions while if they gain electrons the form negatively charged ions
Answer:
mercury, magnesium, water and gasoline.
Explanation:
Density:
Density is equal to the mass of substance divided by its volume.
Units:
SI unit of density is Kg/m3.
Other units are given below,
g/cm3, g/mL , kg/L
The liquid with higher density will sink in bottom while the liquid with lower density will float.
In given samples,
density of water = 1 g/mL
density of mercury = 13.6 g/mL
density of gasoline = 0.70 g/mL
density of magnesium = 1.7 g/mL
So on the basis of given density values mercury will sink in bottom then above it magnesium will present than water and above on these three gasoline will present.
Answer:
copper(ll)oxide
Explanation:
Limit reagent is a reagent that finished thereby stopping the reaction.
2NH3(g) + 3CuO(s)---> N2(g) + 3Cu(s) + 3H20(g)
molar mass of of ammonia = 17.031 × 2 (stiochiometry mole) = 34.06 g/mol
molar mass of CuO = 79.545 × 3 = 238.635 g/mol
molar mass of Nitrogen gas = 28.0134 g/mol
34.06 g of NH3 need 238.635 of CuO to produce 28.0134 of Nitrogen gas
238.635g produce 28.0134 g
x gram of CuO produce 26 gram of Nitrogen gas
x gram = ( 26 × 238.635 ) / 28.0134 = 221.484 g
also
34.06 g of ammonia produces 28.0134g of nitogen gas
y gram of ammonia produce 26g
y gram = (26× 34.06) / 28.0134 g = 31.61 g
but the 34 g of ammonia was used in the reaction and 31.61 reacted leaving and 2.39 g of ammonia gas
The limiting reagent therefore is copper(ll)oxide
