Answer:
Both statements I, and II are true
Explanation:
I)One is true.The number of protons of the element is the defining characteristic of it. This is, if we take a proton or add a proton to a nucleus we will be changing the element. Therefore, the number of protons is the same for all neutral and not neutral atoms of that element.
II)Two is true. If an atom is neutral, it will have the same number of electrons and protons. As the number of protons for an element cannot change (see I), then the number of electrons will be the same for all neutral atoms of this element.
III)Three is false. We can have a neutral atoms of the same element with different number of neutrons, as neutrons do not change the charge of the atom(they change their mass, though). These are called Isotopes.
Threshhold frequency is defined as the minimum light frequency necessary to start photo-electric emission from the surface. This frequency is just effecient enough to emit electrons without any additional force or energy. this minimum frequency creates the necessary result that is sought by the person. The photo electric emission for certain metals can occir with threshhold frequency. The importance of this threshhold frequency lies in the fact that this has been used to create numerous instruments like amplifiers for use of people.
Answer:
Argon, Lithium and Potassium
Explanation:
Answer:
I.72m/s²
II.8m/s²
Explanation:
acceleration equal velocity² divided by length
The solution for this problem:
Given:
f1 = 0.89 Hz
f2 = 0.63 Hz
Δm = m2 - m1 = 0.603 kg
The frequency of mass-spring oscillation is:
f = (1/2π)√(k/m)
k = m(2πf)²
Then we know that k is constant for both trials, we have:
k = k
m1(2πf1)² = m2(2πf2)²
m1 = m2(f2/f1)²
m1 = (m1+Δm)(f2/f1)²
m1 = Δm/((f1/f2)²-1)
m 1 = 0.603/
(0.89/0.63)^2 – 1
= 0.609 kg or 0.61kg or 610 g
