Answer:
c. natural force or pull toward the earth
Explanation:
Gravity of the earth is the force of attraction that it naturally possesses to attract any mass.
An apple falls on the earth due to this force of gravity.
The force of gravity near to the surface of the earth is given as:
where:
m= mass of the body
g= acceleration due to gravity
The variation of the gravitational force with height is given as:

where:

where
R = radius of the earth 
Answer:
D
Explanation:
The answer is Niels Bohr's planetary model, the difference between this model and all of the other models is that the Bohr's PM Is more of layers of
Nucleus - Protons and Neutrons
Electron Orbital - Period 1 Elements
2 electrons
Electron Orbital - Period 2 Elements
8 electrons
Electron Orbital - Period 3 Elements
8 electrons
If that made sense-
Answer:
The correct option is a
Explanation:
The alpha particle has the lowest penetrating power of the trio of alpha, beta and gamma particles and can be stopped by a sheet of paper and hence cannot penetrate a human skin. Beta particle has a higher penetrating power than alpha particle (some of it penetrates the human skin and some do not) while the gamma particle has the highest penetrating power (with all of it penetrating the human skin).
From the above description, it can be deduced that the alpha particle will stay and interact with the hand (because of its low penetrating power) as the remaining particles move through the skin.
<em>Soil can be described as the C. Loose covering of weathered rocks and decaying organic matter.</em>
Answer:
The minimum frequency required to ionize the photon is 111.31 ×
Hertz
Given:
Energy = 378 
To find:
Minimum frequency of light required to ionize magnesium = ?
Formula used:
The energy of photon of light is given by,
E = h v
Where E = Energy of magnesium
h = planks constant
v = minimum frequency of photon
Solution:
The energy of photon of light is given by,
E = h v
Where E = Energy of magnesium
h = planks constant
v = minimum frequency of photon
738 ×
= 6.63 ×
× v
v = 111.31 ×
Hertz
The minimum frequency required to ionize the photon is 111.31 ×
Hertz