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:
of the reaction is -6313 kJ/mol
of the reaction is -6312 kJ/mol
Explanation:
Therefore, of the reaction is -6313 kJ/mol.
The chemical reaction in bomb calorimeter is as follows.
Therefore, of the reaction is -6312 kJ/mol.
True
Explanation:
Harry Hess in 1961 resurrected Wegener's continental drift hypothesis and also he mantle convection idea of Arthur Holmes by postulating the theory of sea floor spreading.
- After Wegener's postulation of the continental drift hypothesis, not much was done.
- It was only around 1931 that Arthur Holmes came up with the idea of a convecting mantle.
- After the second world war passed, new instruments were used to investigate and map the ocean floor.
- Through this, Arthur Holmes came up with the idea of a spreading sea floor.
- This gave a full gleam picture to the idea of a moving earth and the more accepted terminology of "Plate tectonics " came to the fore.
Learn more:
Sea floor spreading brainly.com/question/9912731
Continental drift brainly.com/question/5002949
#learnwithBrainly
It’s jingju because it was established in 1955
Answer:
19.5g
Explanation:
Given parameters:
Volume of propane gas = 9.95L
Unknown:
Mass of propane gas = ?
Solution:
To solve this problem, find the number of moles first.
At STP;
22.4L of gas makes up 1 mole
9.95L of gas will have a 
= 0.44mole
So;
Mass of propane gas = number of moles x molar mass
Molar mass of propane = 3(12) + 8(1) = 44g/mol
Mass = 0.44 x 44 = 19.5g
