Answer: be found in group 17 and be highly reactive
Explanation:
Elements are distributed in groups and periods in a periodic table.
Elements that belong to same groups will show similar chemical properties because they have same number of valence electrons.
Flourine, chlorine, bromine and iodine are elements which belong to Group 17. All of them contain 7 valence electrons each and need one electron to complete their octet.
The chemical reactivity of elements is governed by the valence electrons present in the element and thus all of them are highly reactive.
Answer:
Isothermal : P2 = ( P1V1 / V2 ) , work-done 
Adiabatic : : P2 =
, work-done =
W = 
Explanation:
initial temperature : T
Pressure : P
initial volume : V1
Final volume : V2
A) If expansion was isothermal calculate final pressure and work-done
we use the gas laws
= PIVI = P2V2
Hence : P2 = ( P1V1 / V2 )
work-done :

B) If the expansion was Adiabatic show the Final pressure and work-done
final pressure

where y = 5/3
hence : P2 = 
Work-done
W = 
Where 
Answer:
The cannon has an initial speed of 13.25 m/s.
Explanation:
The launched cannonball is an example of a projectile. Thus, its launch speed can be determined by the application of the formula;
R = u
Where: R is the range of the projectile, u is its initial speed, H is the height of the cliff and g is the gravitaty.
R = 26.3 m, H = 19.3 m, g = 9.8 m/
.
So that:
26.3 = u
=
x 
691.69 =
x 
= 
= 
= 175.6104
⇒ u = 
= 13.2518
u = 13.25 m/s
The initial speed of the cannon is 13.25 m/s.
Answer: coal
Explanation: Nonrenewable energy resources include coal, natural gas, oil, and nuclear energy. Once these resources are used up, they cannot be replaced, which is a major problem for humanity as we are currently dependent on them to supply most of our energy needs