Answer:
a) 1.866 × 10 ⁻¹⁹ J b) 3.685 × 10⁻¹⁹ J
Explanation:
the constants involved are
h ( Planck constant) = 6.626 × 10⁻³⁴ m² kg/s
Me of electron = 9.109 × 10 ⁻³¹ kg
speed of light = 3.0 × 10 ⁸ m/s
a) the Ek ( kinetic energy of the dislodged electron) = 0.5 mu²
Ek = 0.5 × 9.109 × 10⁻³¹ × ( 6.40 × 10⁵ )² = 1.866 × 10 ⁻¹⁹ J
b) Φ ( minimum energy needed to dislodge the electron ) can be calculated by this formula
hv = Φ + Ek
where Ek = 1.866 × 10 ⁻¹⁹ J
v ( threshold frequency ) = c / λ where c is the speed of light and λ is the wavelength of light = 358.1 nm = 3.581 × 10⁻⁷ m
v = ( 3.0 × 10 ⁸ m/s ) / (3.581 × 10⁻⁷ m ) = 8.378 × 10¹⁴ s⁻¹
hv = 6.626 × 10⁻³⁴ m² kg/s × 8.378 × 10¹⁴ s⁻¹ = 5.551 × 10⁻¹⁹ J
5.551 × 10⁻¹⁹ J = 1.866 × 10 ⁻¹⁹ J + Φ
Φ = 5.551 × 10⁻¹⁹ J - 1.866 × 10 ⁻¹⁹ J = 3.685 × 10⁻¹⁹ J
Answer:
B. 8
Explanation:
because I learned that in 6th
Answer:
C). The Bohr-Rutherford model
Explanation:
The 'Bohr-Rutherford model' of the atom failed to elaborate on the attraction between some substances. It essentially targeted hydrogen atoms and failed to explain its stability across multi-electrons. The nature and processes of the chemical reactions remained unillustrated and thus, this is the key drawback of this model. Thus, <u>option C</u> is the correct answer.
Unsaturated hydrocarbons are those in which each carbon atom is attached to as many hydrogen atoms as it possibly can. There can be no double bonds or non-hydrogen functional groups, since these detract from the maximum possible number of hydrogens that each carbon can be attached to (in the case of double bonds, two carbons are bonded to each other when they could alternately be bonded to one more hydrogen each).
All of the alkanes (including the cycloalkanes) are saturated hydrocarbons. Substituted alkanes, alkenes, alkynes, and their cyclic counterparts are all unsaturated.
To solve this problem, let us all convert the mass of
each element into number of moles using the formula:
moles = mass / molar mass
Where,
molar mass K = 39.10 g / mol
<span>molar mass Cl = 35.45 g / mol</span>
molar mass O = 16 g / mol
<span>and mass O = 13 g – 4.15 g
– 3.76 g = 5.09 g</span>
moles K = 4.15
g / (39.10 g / mol) = 0.106 mol
<span>moles Cl = 3.76 g / (35.45 g / mol) = 0.106 mol</span>
moles O = 5.09 g / (16 g /
mol) = 0.318 mol
The ratio becomes:
0.106 K: 0.106 Cl: 0.318 O
We divide all numbers with
the smallest number, in this case 0.106. This becomes:
K: Cl: 3O
Therefore the empirical formula
is:
