The periodic classification is an arrangement of the elements
atomic weights
isotopic weights
molecular weights
atomic numbers
Correct answer is D
Elements in the periodic table are arranged according to their atomic number (proton number). Electronegativity increase from left to right while atomic radius increases down the group
Elements in the periodic table are arranged according to their atomic number (proton number). Electronegativity increase from left to right while atomic radius increases down the group
Which of the following statements is correct about the periodic table?
Elements in the same period have the same number of valence electrons
The valence electrons of the elements in the same period increase progressively across the period
Elements in the same group have the same number of electron shells
The non-metallic Properties of the elements tend to decrease across each period
Correct answer is B
The valence electrons refer to the number of electrons in the outer shell. Across a period (horizontal row), the valence electron increases.
I, II, III and IV
I and II only
II only
III and IV only
Correct answer is D
The solubility of a gas decreases with an increase in temperature and a decrease in pressure.
collisions are perfectly elastic
forces of repulsion exist
forces of repulsion and attraction are in equilibrium
collisions are inelastic
Correct answer is A
According to one of the kinetic theories of gases, When collisions occur, the molecules lose no kinetic energy; that is, the collisions are said to be perfectly elastic.
Al and Mg
Zn and Fe
Zn and Pb
Pb and H
Correct answer is A
No explanation has been provided for this answer.