Answer:
how large a magnetic field would you experience = 8.16 x 10∧-4T
Explanation:
I = 20KA = 20,000A
r = 4.9 m
how large a magnetic field would you experience = u.I/2πr
how large a magnetic field would you experience = (4π x10∧-7) × 20000/2π × 4.9
how large a magnetic field would you experience = 8.16 x 10∧-4T
The energy carried by the incident light is
where h is the Planck constant and f is the frequency of the light. The threshold frequency is the frequency that corresponds to the minimum energy needed to eject the electrons from the metal, so if we substitute the threshold frequency in the formula, we get the minimum energy the light must have to eject the electrons:
Speed equals distance divided by time, so 350 divided by 2.5 equals 140 kilometers per hour.
Answer:
A. They have the same atomic numbers.
Explanation:
Elements are defined based on the atomic number, which is the number of protons in the nucleus: this means that atoms of the same element have always the same number of protons in their nuclei (and so, always the same atomic number).
The other choices are wrong because:
B. They have the same average atomic masses. --> this is false for isotopes, which are atoms of the same element having a different number of neutrons. Since the atomic mass is calculated from the sum of the masses of protons and neutrons in the nucleus, two isotopes of the same element have different atomic mass
C. They have the same number of electron shells. --> this can be false when an atom of an element loses/gains an electron, becoming an ion: in that case, the number of electron shells can change, since the number of electrons has changed.
D. They have the same number of electrons in their outermost shells. --> this is also false in case one of the atoms is an ion, since the number of electrons is different.
Answer: something must drop it over
Explanation:
