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 I’m not really sure yet
Acceleration = (change in speed) / (time for the change)
change in speed = (speed at the end) minus (speed at the beginning)
change in speed = (zero) minus (28 m/s) = -28 m/s
Acceleration = (-28 m/s) / (13 sec)
Acceleration = -2.15 m/s²
In linear motion , when a body moves with uniform velocity , in time t , its linear displacement will be ;
S = r∅ S = vt
r∅ = vt
r.∅ / t = v
As
v = rw
where ∅ = 90° is the angle between between radius vector r and angular velocity w (omega )
In case ∅ ≠ 90° , we can write v = r w sin∅
It gives us v = w× r