Answer is: beryllium-10.
The diagram shows that atom has 4 protons, 5 neutrons and 2 valence electrons.
Atomic number is the number of protons, which is characteristic of a chemical element, beryllium (Be) is an element with atomic number 4.
Two valence electrons means that atom is from 2. group of periodic table, only beryllium is from that group; sodium (1. group), boron (13. group) and carbon (14. group).
Beryllium-10 has 6 neutrons, so it is isotope (different number of neutrons or mass number).
Answer:Nuclear binding energy is the energy needed to separate nuclear particles
The strong nuclear force holds an atom’s protons and neutrons together
Nuclear binding energy can be calculated using E=mc2
Explanation:
Answer:
<em>A not reasonable explanation for an aerospace engineer designs a rocket to have three stages is</em>:
- <u><em>A. To simplify the design of the rocket</em></u>
Explanation:
A <em>three stages rocket</em> permits to separate the fuel compartments. The rocket must be launched with a huge amount of fuel to last the entire travel. Then the initial mass of the rocket and the fuel is considerably large.
As the rocket flies, part of the fuel is consumed and so some compartements may be separated and removed decreasing the mass of the rocket as it flies (<em>option D. </em>is a reasonable explanation), so the rocket only carries the necessary mass (<em>statement B</em>. is a reasonable explanation).
As the rocket moves away from Earth, the gravitational force decreases and, in the space, the amount of thrust needed is lesser, which the aerospace engineers take into account for the design (choice C. is a reasonable explanation).
The only <em>not reasonable explanation to design a three stage rocket</em> is to <em>simplify the design of the rocket</em>: designing a rocket with three modules each with different features, functions, and the detachment mechanisms brings lot of complex problems to solve. So, o<em>ption A. </em>is the correct answer.
Answer:
0.245 moles
Explanation:
moles of lithium = 2*moles of Li2SO4
so moles of LI2SO4=2.94*10^23/(2*6*10^23)=0.245
The answer is C to achieve an octet of valence electrons so they become stable
