The answer would be:
B. Chlorine, iodine and Fluorine
Barium has 2 valence electrons. To satisfy the BaX₂ , this would mean that Barium will need to give one of each of its electrons. The elements that need 1 electron would be those that have 7 valence electrons to complete the octet. These elements would fall in group 7 or halogens. Chlorine, iodine and fluorine are all in Group 7, so this would be the best choice.
The answer is D=M/V hope it helps!!
We know,
V= f× wavelength
10.5= f×0.15
f=10.5/0.15
f= 70 Hz
Answer:
5308.34 N/C
Explanation:
Given:
Surface density of each plate (σ) = 47.0 nC/m² = 
Separation between the plates (d) = 2.20 cm
We know, from Gauss law for a thin sheet of plate that, the electric field at a point near the sheet of surface density 'σ' is given as:

Now, as the plates are oppositely charged, so the electric field in the region between the plates will be in same direction and thus their magnitudes gets added up. Therefore,

Now, plug in
for 'σ' and
for
and solve for the electric field. This gives,

Therefore, the electric field between the plates has a magnitude of 5308.34 N/C
Answer:
a) 2cm³
b) 100 g/cm³
Explanation:
a- 9-7= 2cm³
b- 200 divided by 2= 100 g/cm³
Hope this helps... correct me if i'm wrong