2-7-1
<h3>Further explanation
</h3>
Electrons can move the shell up or down by releasing energy or absorbing energy
Excited electrons show higher electron transfer to the shell by absorbing energy
So it can be concluded that there are 2 conditions:
Ground state is the state of electrons filling shell with the lowest energy levels.
Excited state is the state of electrons which occupies a higher energy level
The state of excited electrons can be seen from the presence of electrons which do not fill the skin completely but fill the skin afterward
2-7-1
From its 8 electron configuration, filling 3 shells, 2 electrons in the firs shell, 7 electrons in the second shell and 1 electron in the third shell
the electrons in the third shell should fill the electrons in the second shell first according to Aufbau rule (lower energy shells)

A glow stick will glow longer at lower temperatures than at room temperature, one can infer from the observation. Temperature and reaction time are the test variables.
We notice in this reaction that a glow stick stored in the freezer lights for a longer period of time than a glow stick stored at normal temperature. This implies that temperature affects how long a response lasts.
The most straightforward explanation for this observation is that glow sticks glow longer in colder temperatures than they do at room temperature; as a result, glow sticks kept in the freezer are observed to glow longer than glow sticks kept at room temperature.
To learn more about chemicals to the given link:
brainly.com/question/24600141
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Answer:
a thermos bottle uses a vacuum to keep heat in the thermos.
Answer:is 1.08 kg
Explanation:
Just got it wrong and it gave me the answer