1. Mass number of Lithium-7: 7
Explanation:
- The atomic number of an element is equal to the number of protons inside its nucleus
- The mass number of an element is equal to the number of protons+neutrons inside its nucleus
The nomenclature "Element-X", where X is the number of protons+neutrons, is used to indicate the mass number of the isotope. Therefore, an isotope of LIthium-7 has a mass number of 7.
2. An isotope of lithium-8 contains 5 neutrons
Explanation:
Lithium is the third element of the periodic table, so its atomic number is 3, which means that it has 3 protons.
In this problem, we have an isotope of lithium-8, which means that it has a mass number of 8: so, the sum of neutrons+protons in its nucleus is 8:
where p is the number of protons and n the number of neutrons. However, we also know that for lithium p=3, so we can find the number of neutrons:
<h2>
Electric field at the location of the charge is 1250 N/C</h2>
Explanation:
Electric field is the ratio of force and charge.
Force, F = 3.00 mN = 3 x 10⁻³ N
Charge, q = 2.40 μC = 2.40 x 10⁻⁶ C
We have
Electric field at the location of the charge is 1250 N/C
Answer:
an apple falling off a tree
Explanation: