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).
Mass defect for oxygen-16 = 0. 13261 amu, in the kilograms the mass defect equals to 2.20 × 10⁻²⁸ kg.
<h3>What is mass defect?</h3>
Mass defect is the difference between the mass of of an whole atom and the combined mass of its individual particles present in that atom.
We know that, 1 amu = 1.6 × 10⁻²⁷ kg
Given that, mass defect for oxygen-16 = 0.13261 amu
To calculate this defect in terms of kilograms, we have to convert into kg unit as:
0.13261 amu = 0.13261 amu × 1.6 × 10⁻²⁷ kg/amu
0.13261 amu = 2.20 × 10⁻²⁸ kg
Hence option (2) is correct.
To know more about Mass defect, visit the below link:
brainly.com/question/4334375
Answer:
01) Cu tting hair is a physical change. reason-1
02) Cooking can be either one, but I would choose chemical reason-3
03) Ice cream melting is a physical change reason-2
Explanation:
They use it because it's standerize and evidence vase
