Answer: 2. magnesium
Explanation: correct spelling...?
Because H is a non-metal, it has the highest electronegativity. Option (1) H is correct.
Hope this would help~
Potential energy is energy due to an object's height above the ground.
Potential energy = mass x gravity x height
Kinetic energy is energy due to the motion of the object.
Kinetic energy = 1/2 x mass x velocity²
1.
The ball is not moving and is at a height above the ground so it has only potential energy.
P.E = 2 x 9.81 x 40
P.E = 784.8 J
2.
The ball is moving and has a height above the Earth's surface so it has both kinetic and potential energy.
P.E = same as part 1 = 784.8 J
K.E = 1/2 x 2 x 5²
K.E = 25 J
3.
The ball has no height above the Earth's surface and is moving so it has only kinetic energy.
K.E = 1/2 x 2 x 10²
K.E = 100 J
4.
50000 = 1/2 x 1000 x v²
v = 10 m/s
5.
39200 = 200 x 9.81 x h
h = 20.0 m
6.
12.5 = 1/2 x 1 x v²
v = 5 m/s
98 = 1 x 9.81 x h
h = 10.0 m
The equation for calculating a mass is as follows:
m=n×M
Molar mass (M) we can determine from Ar that can read in a periodical table, and a number of moles we can calculate from the available date for N:
n(H2SO4)=N/NA
n(H2SO4)= 1.7×10²³ / 6 × 10²³
n(H2SO4)= 0.3 mole
Now we can calculate a mass of H2SO4:
m(H2SO4) = n×M = 0.3 × 98 = 27.8 g
Ans is B.Bromine. Only two elements are liquid at room temperature ( mercury and Bromine) . Helium and chlorine, arsenic are gases.
