The question is incomplete. Complete question is:
Which list represents the classification of the
elements nitrogen, neon, magnesium, and
silicon, respectively?
(1) metal, metalloid, nonmetal, noble gas
(2) nonmetal, noble gas, metal, metalloid
(3) nonmetal, metalloid, noble gas, metal
(4) noble gas, metal, metalloid, nonmetal
.................................................................................................................
Answer: The correct answer is option 2) nonmetal, noble gas, metal, metalloid
Reason:
1) Non-metal are bad conductors of electricity. Also non-metal are electronegative in nature. Hence, among the provided elements, nitrogen satisfied the criteria. Hence, it is a non-metal.
2) Noble gas are the elements which have completely filled outermost shell. Hence, among the provided elements, Neon satisfied the criteria.
3) Metal are good conductors of electricity. Also metal are electropositive in nature. Hence, among the provided elements, magnesium satisfied the criteria. Hence, it is a metal.
4) Metalloid have conductivity better than non-metals but poor than conductors. Hence, among the provided elements, Silicon satisfied the criteria. Hence, it is a metalloid.
Answer:
The mass percentage of nitrogen in the sample is 1.96%.
Explanation:
21.0 mL of 0.150 M HCl
Moles of hydrogen chloride = n
Volume of hydrogen chloride solution = 21.0 mL = 0.021 L
Molarity of the hydrogen chloride = 0.150 M


According to recation, 1 mole of HCl neutralizes 1 mole ammonia.Then 0.00315 moles of HCl will neutrtalize:
of ammonia
1 mole of ammonia has 1 mole of nitrogen atom . Then 0.00315 moles of ammonia will have = 1 × 0.00315 mol = 0.00135 mol
Mass of 0.00315 moles of nitrogen= 0.00315 mol × 14 g/mol = 0.0441 g
Mass of the sample = 2.25 g
The mass percentage of nitrogen in the sample:

The recessive trait disappears in an offspring that is genetically crossed. TRUE.