Answer:
10
Explanation:
I did that already. You got beo
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
The most appropriate answer is C !! Cs is most electropositive and thus least electronegative !!
The melting points of sugar and salt are above 20°C.
<h3>What is melting point?</h3>
The melting points of substances refer to the temperature at which solid substances gain enough energy to become liquids.
The room temperature is approximately 20°C. At this temperature, sugar and salt are solids. This means that the melting temperature of both substances is above 20°C.
More specifically, sugar will melt around 180 °C while salt will melt at a temperature slightly above 800 °C.
More on melting points can be found here: brainly.com/question/25777663
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Thermal energy equation is;
Q = mcΔθ
Q = Thermal energy
m = mass
c = specific heat
Δθ = Temperature difference
the hot cup of coffee has a higher temperature. But the mass of coffee is very low compared to the mass of water in swimming pool. The maximum temperature for coffee only can go up to 100 ⁰C since the boiling point of water is 100 ⁰C. But the mass of water in swimming pool is very large and the thermal enegy is very high compared to the coffee cup due to that reason.
