Answer:
AS we move from bottom to top on periodic table shielding decreased.
Explanation:
As we move from left to right across the periodic table the number of valance electrons in an atom increase. The atomic size tend to decrease in same period of periodic table because the electrons are added with in the same shell. When the electron are added, at the same time protons are also added in the nucleus. The positive charge is going to increase and this charge is greater in effect than the charge of electrons. This effect lead to the greater nuclear attraction.
As we move down the group atomic radii increased with increase of atomic number. The addition of electron in next level cause the atomic radii to increased. The hold of nucleus on valance shell become weaker because of shielding of electrons thus size of atom increased.
As we move from bottom to top the energy level decreased because of decreased in electron thus shielding decreased and atomic size also decreased.
Answer:
45 neutrons
Explanation:
Bromine has 35 protons and a mass number of 80. a) How many neutrons does the atom of bromine have? The mass number = protons + neutrons. Bromine has a mass number of 80 and 35 protons so 80-35 = 45 neutrons.
The heat absorbed by the water is
Q = 500 (4.18) (32.2 - 25)
Q = 15048 J
The enthalpy of fusion of the sodium acetate is:
<span>ΔHf = Q / m
</span><span>ΔHf = 15048 / 100
</span>ΔHf = 150.48 J/g
Answer:
A)21
Explanation:
To know the difference between the number of electrons in the two atoms, we must first know the number of electrons in the atoms.
For Selenium, Se, we have 34 electrons. The element is in group 6 on the periodic table.
Aluminum on the other hand is in the Boron family with a total of 13 electrons.
The difference,( 34-13) electrons gives a total of 21 electrons
Answer:
Explanation:
91.4
grams
Explanation:
C
=
m
o
l
v
o
l
u
m
e
2.45
M
=
m
o
l
0.5
L
2.45
M
⋅
0.5
L
=
m
o
l
m
o
l
=
1.225
Convert no. of moles to grams using the atomic mass of K + Cl
1.225
m
o
l
⋅
(
39.1
+
35.5
)
g
m
o
l
1.225
m
o
l
⋅
74.6
g
m
o
l
=
1.225
⋅
74.6
g
=
91.4
g
