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 rain gauge measures rain shadow units millimetres
I do not agree with the statement.
The "substance" can be a compound. It's "pure"
as long as there's nothing else in it but its name.
'Pure' water is 100% H₂O with nothing else in it.
'Pure' table salt is 100% NaCl with nothing else in it.
'Pure' carbon dioxide is 100% CO₂ with nothing else in it.
These example substances are all compounds, not elements.
Explanation:
Given that,
Wavelength of the light, 
(a) Slit width, 
The angle that locates the first dark fringe is given by :
(b) Slit width, 
The angle that locates the first dark fringe is given by :
Hence, this is the required solution.
Answer: The spring constant is K=392.4N/m
Explanation:
According to hook's law the applied force F will be directly proportional to the extension e produced provided the spring is not distorted
The force F=ke
Where k=spring constant
e= Extention produced
h=2m
Given that
e=20cm to meter 20/100= 0.2m
m=100g to kg m=100/1000= 0.1kg
But F=mg
Ignoring air resistance
assuming g=9.81m/s²
Since the compression causes the plastic ball to poses potential energy hence energy stored in the spring
E=1/2ke²=mgh
Substituting our values to find k
First we make k subject of formula
k=2mgh/e²
k=2*0.1*9.81*2/0.1²
K=3.921/0.01
K=392.4N/m
