A thin gold foil .
Hope this helps
Answer: 6.65 bullfrogs per square
kilometer
Explanation:
The formula to calculate the population density will be:
= N/A
where,
N = total population = 452
A = land area = 68km²
Therefore, population density will be:
= N/A
= 452/68
= 6.65 bullfrogs per square
kilometer
Answer:
Option D. Electron clouds with a total of 7 electrons.
Explanation:
For an atom to be neutral (i.e having a charge of zero), the number of protons and electrons must be equal.
Thus, to know which option is correct, we shall determine the number of protons and electrons in the nitrogen atom as given in the question above.
From the question given above, we obtained the following:
Atomic number = 7
Mass number = 14
Number of protons =?
Number of electrons =.?
Next, we shall determine the number of protons in the nitrogen atom as follow:
Atomic number of an element is simply defined as the number of protons in the atom of the element. Mathematically,
Atomic number = proton number
Atomic number = 7
Therefore,
Number of protons = 7
Next, we shall determine the number of electrons in nitrogen atom as follow:
Since the atom is neutral (i.e having a charge of zero), the number of protons and electrons are equal i.e
Number of protons = number of electrons
Number of protons = 7
Therefore,
Number of electrons = 7
Thus, the nitrogen atom must have 7 electrons in order for it to be neutral.
**** Check ****
Charge of atom = Proton – Electron
Charge = 0
Proton = 7
Electron = 7
Charge of atom = Proton – Electron
0 = 7 – 7
0 = 0
Circular lines on topographic map is called Contour lines these lines shown on two dimension map and depict elevation on the ground . the distance of each contour line is set to represent a certain level of elevation with zero being sea level . mostly map use distance between coutour lines is 10 m
