heating to saturation and drying
filtering and evaporation to dryness
filtering, washing and drying
crystallizing and allowing to cool
Correct answer is C
No explanation has been provided for this answer.
The metallic bond in magnesium is stronger than that in calcium because magnesium has a
larger atomic size.
smaller atomic size
greater number of valence electrons
lower melting point
Correct answer is B
- Magnessium has a stronger metallic bond than calcium because it has smaller atomic radius.
- Atomic radius decreases across a period and increases down a group.
Which of the following arrangement of elements is in decreasing order of electronegativity?
Na, Mg, Al, Si, P
Na, A1, Mg, P, Si
P, Mg, Na, Si, Al
P, Si, Al, Mg, Na
Correct answer is D
- Reactivity series is K > Na > Ca > Mg > Al > Zn > Fe > Pb > H > Cu > Hg > Ag > Au.
-Very Electropositive Metals Most active metals have low electronegativities
Which of the following metals does not react with water to produce hydrogen?
Copper
Potassium
Sodium
Zinc
Correct answer is A
Most alkali metals and alkaline earth metals react with water to produce hydrogen. The alkali metals comprise Group 1 of the periodic table, and include lithium, sodium, potassium, etc.
- Zinc is not much reactive with cold or room temperature water but reacts with steam to form zinc oxide and liberate hydrogen gas.
- Copper lies below hydrogen in the activity series of metals, therefore it can not displace hydrogen from water
"Electrons always occupy the lowest empty energy level" is a statement of
Aufbau Principle
Hund's rule
Pauli Exclusion Principle
Periodic law
Correct answer is A
- The Aufbau principle states that electrons fill lower-energy atomic orbitals before filling higher-energy ones