Answer:
6 and 14 respectively
Explanation:
proton number = atomic number
mass number = proton number + neutron number
since
- p.n = a.n = 6
- m.n = p.n + n.n
- m.n = 6 + 8 = 14
- m.n = 14
No, only average speed can be calculated from the distance of 90 meters and the time 3 seconds hope this helps
Answer:
Explanation:
a ) The motion is one dimensional , so motion is along x - axis , starting from origin ( 0 , 0 )
b ) Initial velocity is 18.5 m /s when boat is situated at origin . When he displaces by 250 m along x axis and his position is ( 250 , 0 ) along x axis , his velocity becomes 36 m /s . Both his velocity and acceleration is along x - axis.
c ) Initial velocity vi = 18.5 m /s
final velocity vf = 36 m/s
Displacement x = 250 m
Acceleration a = ?
Most appropriate formula is given below .
vf² = vi² + 2 a x
2ax = vf² - vi²
x = ( vf² - vi² ) / 2 a
d )
Putting the given values
36² - 18.5² / 2 x 250
= 1296 - 342.25 / 500
= 1.9 m /s².
f ) Time interval t = ?
Required formula
vf = vi + at
t = (vf - vi ) / a
Putting the values
t = (30 - 18.5) / 1.9
= 6.05 second .
Answer:
Option b. Effective nuclear charge increases as we move to the right across a row in the periodic table
Explanation:
The <em>effective nuclear charge </em>is a measure of how strong the protons in the nucleus of an atom attract the outermost electrons of such atom.
The <em>effective nuclear charge</em> is the net positive charge experienced by valence electrons and is calculated (as an approximation) by the equation: Zeff = Z – S, where Z is the atomic number and S is the number of shielding electrons.
The shielding electrons are those electrons in between the interesting electrons and the nucleus of the atom.
Since the shielding electrons are closer to the nucleus, they repel the outermost electrons and so cancel some of the attraction exerted by the positive charge of the nucleus, meaning that the outermost electrons feel less the efect of attraction of the protons. That is why in the equation of Zeff, the shielding electrons (S) subtract the total from the atomic number Z.
The <em>effective nuclear charge</em>, then, is responsible for some properties and trends in the periodic table. Here, you can see how this explains the trend of the atomic radius (size of the atom) accross a row in the periodic table.
- As the<em> effective nuclear charge</em> is larger, in a same row of the periodic table, the shielding effect is lower, the outermost electrons are more strongly attracted by the nucleus, and the size of the atoms decrease. That is why as we move to the right in the periodic table, the size of the atoms decrease.
Given Information:
Index of refraction of glass = n₂ = 1.42
Angle of reflection = θ₁
Angle of refraction in terms of angle of reflection = θ₂ = 0.5θ₁
Required Information:
Angle of refraction = θ₂ = ?
Answer:
Angle of refraction = θ₂ = 44.76°
Explanation:
We know from the Snell's law that
n₁sinθ₁ = n₂sinθ₂
Where n₁ is index of refraction of air and n₂ is index of refraction of glass, θ₁ is the angle of reflection and θ₂ is the angle of refraction.
Assuming n₁ = 1
1*sinθ₁ = 1.42*sinθ₂
since θ₂ = 0.5θ₁
1*sinθ₁ = 1.42*sin0.5θ₁
1/1.42 = sin0.5θ₁/sinθ₁
sin⁻¹(1/1.42) = sin⁻¹(sin0.5θ₁/sinθ₁)
44.76° = 0.5θ₁
θ₁ = 44.76°/0.5
θ₁ = 89.52°
So the angle of refraction is
θ₂ = 0.5(89.52°)
θ₂ = 44.76°