Answer:
C
Explanation:
Characteristics used to classify stars include color, temperature, size, composition, and brightness.
Lets name the unknown metal as M. Cation would be M³⁺.
the molecular formula of the compound is M₂(SO₄)₃
the mass of one mole - (molar mass of M x2 + 3 x molar mass of SO₄²⁻)
= 2M + 96 x 3
= 2M + 288
In 1 mol if there's 72.07% of sulphate ,
then 72.07 % corresponds to 288 g
1 % is then - 288/72.07
100 % of the compound - 288/72.07 x 100
molar mass of the compound - 399.6 g/mol
mass of 2M - 399.6 - 288 = 111.6 g
molar mass of M - 111.6 /2 = 55.8 g/mol
the element with molar mass of 55.8 is Fe.
Unknown metal is iron(III) , Fe³⁺
To work out the kinetic energy of an object, you use the formula:
E = 0.5 x (mass) x (velocity)^2
One important thing, though. The units MUST be consistent. Mass needs to be in kilograms, and velocity in metres per second.
To convert the mass form grams to kilograms, we need to divide it by 1000, getting 0.0103 kg. Since the velocity is already in the units we need, we can just plug the numbers into the equation to get:
E = 0.5 x (0.0103 kg) x (48.0)^2 = 11.8656 J = 11.9 J, to 3 significant figures
Hope I helped! xx
