A) It will be 2 covalent bonds
B) covalent bonds occur when there’s 2 atoms that share electrons. In this case by sharing the 2 pairs of valence electrons each atom has a total of 8 valence electrons
To solve the problem it is necessary to apply the definition of Newton's second Law and the definition of density.
Density means the relationship between volume and mass:

While Newton's second law expresses that force is given by
F = ma
Where,
m = mass
a= acceleration (gravity at this case)
In the case of the given data we have to,


In equilibrium, the entire system is equal to zero, therefore


Where,
Weight of balloon
Weight of helium gas
Bouyant force
Then we have,


Replacing the values we have that


Now by ideal gas law we have that



But the relation \frac{n}{m} is equal to the inverse of molar mass, that is



Therefore the pressure of the helium gas assuming it is ideal is 0.61Mpa
Answer:
Change in Displacement
Explanation:
delta/triangle = change
x = displacement
formula (if needed): final x - initial x
Answer:
b. 12.5 mAs, 70 kVp
Explanation:
The given parameter are;
The initial exposure factors := 10 mAs and 70 kVp
The initial Grid Ratio, G.R.₁ = 8:1
The Grid Ratio with which the radiographer desires to increase the scatter absorption, G.R.₂ = 12:1
Given that the lead content in the 12:1 grid, is higher than the lead content in 8:1 grid and that 12:1 grid needs more mAs to compensate, and provides a higher image contrast, the amount of extra mAs is given by the Grid Conversion Factors, GCF, as follows;
The GCF for G.R. 8:1 = 4
The GCF for G.R. 12:1 = 5
Therefore, given that the mAs used by the radiographer for 8:1 Grid Ratio is 10 mAs, the mAs required for a G.R. of 12:1 in order to maintain the same exposure is given as follows;
mAs for G.R. of 12:1 = 10 mAs × 5/4 = 12.5 mAs
Therefore the new exposure factors are;
12.5 mAs, 70 kVp
Answer:
Explanation:
given,
ω₁ = 120 rpm
1 rpm = 
rad/s
= 12.56 rad/s
α = - 4 rad/s²
diameter of disk = 20 cm
final angular velocity = 0
t = 
t = 
t = 3.14 s.
2) 
= 
= 19. 72 radians
3) total angular distance rotated
x = θ R
x = 19.72 × 0.1 = 1.97 m
x = 2 m