Answer:
the answer is b and this how i know
Explanation:
i know that the answer is b because i just did this hope this helps tell me if its wrong it shouldnt be tho
B. barium (Ba)
C. cesium (Cs)
D.rubidium (Rb)
Answer: Option (A) is the correct answer.
Explanation:
When we move downwards in a group then size of the atom increases due to which there is less force of attraction between the nucleus and valence electrons of the atom.
Hence, the atom can easily loose electrons. As a result, reactivity of elements increases down the group.
But when we move across a period then there is decrease in reactivity of the atoms as size of atoms decreases due to which there is an increase in force of attraction between the nucleus and valence electrons.
Therefore, atoms are unable to lose electrons easily.
Hence, magnesium is less reactive than both sodium and strontium. Whereas except magnesium rest all options are more reactive than sodium and strontium.
Thus, we can conclude that magnesium is likely to be less reactive than both strontium and sodium.
11. Consider the elements neon, bromine, and phosphorus. Which has five electrons in its 4p sublevel?
B. ^23 V
C. ^23 Mn
D. ^51 Sb
E. ^51 V
Answer:
E. ^51 V
Atomic number (number of protons in the nucleus): 23
Atomic symbol (on the periodic table of the elements): V
Atomic weight (average mass of the atom): 50.9415
Density: grams per cubic centimeter
Phase at room temperature: Solid
Melting point: 3,470 degrees Fahrenheit (1,910 degrees Celsius)
Boiling point: 6,165 F (3,407 C)
Number of isotopes (atoms of the same element with a different number of neutrons): 2; one stable V-51; one radioactive V-50
Most common isotopes: V-51 (99.75 percent natural abundance)