Answer: The net change in the atoms is the conversion of a neutron to a proton, turning Carbon (6 protons) into Nitrogen (7 protons).
Explanation:
Carbon-14, generated from the atmosphere, has 6 protons and 8 neutrons. That's where the 14 comes from, called the mass number, is the sum of protons and neutrons (6+8=14).
Carbon-14 is radioactive and decays by beta decay. That means one of its neutrons spontaneously turns into a proton, an electron, and a neutrino, according to:

After that, the atom has 7 protons and 7 neutrons, maintaining its mass number but changing its atomic number from 6 to 7, turning into Nitrogen.
Answer:

Explanation:
Hello,
In this case, we use the ideal gas equation to compute the volume as shown below:

Nonetheless we are given mass, for that reason we must compute the moles of gaseous fluorine (molar mass: 38 g/mol) as shown below:

Thus, we compute the volume with the proper ideal gas constant, R:

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Answer:
C The experiment shows that the red substance experienced a chemical change.
Explanation:
Apparently, adding heat caused the red substance to decompose into a gas and a metallic liquid. If it were simply a phase change, the original red substance could be expected to return when the temperature cooled. Because the substance apparently decomposed, it is clearly not an element. At no point in the experiment is there any evidence of a plasma being formed.
The observed decomposition is a chemical change.