The atomic number of an atom would be equal to its mass number if it
has a totally filled valence shell
has a high charge to mass ratio
does not contain neutrons
exhibits isotopy
Correct answer is C
- The mass number of an atom is its total number of protons and neutrons
How many electrons does \({31}_{15}\)P\(^3-\) contain?
12
15
16
18
Correct answer is D
- Phosphorus also has 15 electrons.
- Here we have P3- which means that this atom has gained 3 electrons. So, P3- has 18 electrons.
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