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The atomic number represents the electrons and protons, therefore, if the atomic number of the element is 7 then there are 7 electrons and protons in the element.
In order to determine the amount of neutrons, you would subtract the atomic number from the atomic mass.
Hope this helped!
Answer:

Explanation:
Using Kepler's third law, we can relate the orbital periods of the planets and their average distances from the Sun, as follows:

Where
and
are the orbital periods of Mercury and Earth respectively. We have
and
. Replacing this and solving for

X-ray formation
Energy difference in the first ionization of the same group of elements
Differential linear emission spectra of different elements
Explanation:
The formation of x-ray, energy difference in the first ionization of the same group of elements and differential linear emission spectra of different elements can be justified by the Bohr model of the atom.
- According to Neil Bohr, in an atom, the extranuclear part consists of electrons in specific spherical orbits around the nucleus.
- Bohr's model explained the discrete lines in atomic spectrum of different elements.
- Due to excitation of electrons, some rays are given off. Some of these are energetic like x-rays.
- The energy difference between the first ionization of the same group of elements is a proof that electrons are in specific spherical orbits.
- The higher the energy the level, the ease at which electrons can be removed and the lower the ionization energy.
Learn more:
Bohr model of the atom brainly.com/question/4986277
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Answer:
B. They each contain the same amount of matter.
Explanation:
Scientifically, mass is the amount of matter in an object.
A. Whether an object is big or small does not mean that it will be a certain mass. If you have two objects that are the same size, the denser object will have more mass, and the less dense object will have less mass.
C. The amount of space an object takes up is called the volume.
D. Different combinations and amounts of elements can give you the same mass. Rocks, books and cans of soda are made of different things.
Via half-life equation we have:

Where the initial amount is 50 grams, half-life is 4 minutes, and time elapsed is 12 minutes. By plugging those values in we get:

There is 6.25 grams left of Ra-229 after 12 minutes.