A rapid release of stored up energy
Answer:
seneca
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Answer:
Explanation:
Work function of potassium = 2.29 eV = 3.67 X 10⁻¹⁹ J
So the minimum energy of photon must be equal to 3.67 X 10⁻¹⁹ J .
energy of photon of wavelength λ = hc / λ
where h = 6.67 x 10⁻³⁴
c = 3 x 10⁸
Putting the values in the equation above
6.67 x 10⁻³⁴ x 3 x 10⁸ / λ = 3.67 X 10⁻¹⁹
λ = 6.67 x 10⁻³⁴ x 3 x 10⁸ / 3.67 X 10⁻¹⁹
= 5.452 x 10⁻⁷
= 5452 x 10⁻¹⁰ m
= 5452 A .
PH scale is used to determine how acidic or basic a solution is.
we have been given the hydrogen ion concentration. Using this we can calculate pH,
pH = - log[H⁺]
pH = - log (1 x 10⁻¹ M)
pH = 1
using pH can calculate pOH
pH + pOH = 14
pOH = 14 - 1
pOH = 13
using pOH we can calculate the hydroxide ion concentration
pOH = - log [OH⁻]
[OH⁻] = antilog(-pOH)
[OH⁻] = 10⁻¹³ M
hydroxide ion concentration is 10⁻¹³ M
Answer:
transition elements
Explanation:
Metalloids are elements that have properties intermediate between those of metals and nonmetals. They are sometimes referred to as semi-metals. These materials have recently found great application in materials science and information technology.
Transition elements are however renowned for high densities and tensile strength. The transition elements have the highest density of all the element groups in the periodic table and also have resistance to corrosion. Transition metals such as gold silver and lead are coinage metals because they are resistant to corrosion.
Alkali and alkaline earth metals tarnish easily due to their high reactivity. They are usually very soft metals.
