The nuclear symbol of an element have three parts namely:
- the symbol of an element
- mass number of the element
- atomic number of the element
The general representation is as:
where X is the chemical symbol of the element, A is mass number of the element that is total number of neutrons and protons in the nucleus of an atom, and Z is atomic number of the element that is number of protons in the atom.
Element = Gallium, 
(given)
Number of neutrons = 40 (given)
Let the nuclear symbol be 
. So, we need to determine the values of "?" in the symbol.
Atomic number of Gallium, = 31
Since, atomic number = Number of protons.
So, number of protons of Gallium, = 31
Mass number = number of protons + number of neutrons
Substituting the values:
Mass number = 
So, the nuclear symbol is 
.
Answer:
324.28 cm cubed
Explanation:
13.4 cm x 11.0cm x 2.2cm = 324.28 cm cubed
Answer:
D. A north pole and south pole attract each other
Answer:
D) atomic radii increase from top to bottom of a group
Explanation:
Atomic radii trend along group:
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 the size of atom increases the ionization energy from top to bottom also decreases because it becomes easier to remove the electron because of less nuclear attraction and as more electrons are added the outer electrons becomes more shielded and away from nucleus.
Other options are incorrect because,
A) atomic radii increase from left to right across the period
Correct = atomic radii decreases from left to right across the period
B) ionization energy increases from top to bottom within a family
Correct = ionization energy decreases from top to bottom within a family
C) electronegativity decreases from left to right across a period
Correct = electronegativity increases from left to right across a period
Answer:
D, when there is a large antelope population
Explanation:
I took the k12 test and got it right
