Answer:
Physical and chemical changes are similar because they are both caused by the interaction of two or more particles.
Explanation:
Physical and chemical changes are similar because they are both caused by the interaction of two or more particles. Physical changes occur through vibrations, impacts, and other forms of movement. Chemical changes are caused by the interaction of two or more atoms or molecules.
it would need to gain 2 more for it to achieve a stable configuration
the best way to remember this is the noble gasses all have 8 valence electrons and that they are the most stable elements on the periodic table
Answer:
there are approximately n ≈ 10²² moles
Explanation:
Since the radius of the earth is approximately R=6378 km= 6.378*10⁶ m , then the surface S of the earth would be
S= 4*π*R²
since the water covers 75% of the Earth's surface , the surface covered by water Sw is
Sw=0.75*S
the volume for a surface Sw and a depth D= 3 km = 3000 m ( approximating the volume through a rectangular shape) is
V=Sw*D
the mass of water under a volume V , assuming a density ρ= 1000 kg/m³ is
m=ρ*V
the number of moles n of water ( molecular weight M= 18 g/mole = 1.8*10⁻² kg/mole ) for a mass m is
n = m/M
then
n = m/M = ρ*V/M = ρ*Sw*D/M = 0.75*ρ*S*D/M = 3/4*ρ*4*π*R² *D/M = 3*π*ρ*R² *D/M
n=3*π*ρ*R² *D/M
replacing values
n=3*π*ρ*R² *D/M = 3*π*1000 kg/m³*(6.378*10⁶ m)² *3000 m /(1.8*10⁻² kg/mole) = 3*π*6.378*3/1.8 * 10²⁰ = 100.18 * 10²⁰ ≈ 10²² moles
n ≈ 10²² moles
A neutral atom of potassium has 19 electrons.
W=F*d
W= 500 J
F = 250 N
500 J = 250 N * d
d= 500J/250 N = 2 J/N = 2(N*m)/N = 2 m
Answer is 2 m.
