Because during combustion reaction, heat energy is released and it's this energy that is converted to work
Answer:
C
Explanation:
Br + Br-> Br2 (covalent bond)
bond formation releases energy, as the Br's are in a lower energy state like Br2
Pure chemistry: gain knowledge for own pleasure
Applied chemistry: gain knowledge to know how to use it
Answer:
not valid
Explanation:
Expert judgment is a useful validation method to verify the reliability of an investigation that is defined as “an informed opinion of people with experience in the subject, who are recognized by others as qualified experts in it, and who can give information, evidence, judgments and assessments ”
After submitting an instrument for comparison to the consultation and expert opinion, it must meet two quality criteria: validity and reliability. The validity of content is often established based on two situations, one that concerns the design of a test and the other, the validation of an instrument subject to translation and standardization procedures to adapt it to different cultural meanings. It is here that the task of the expert becomes a fundamental task to eliminate irrelevant aspects, incorporate those that are essential and / or modify those that require it.
Answer:

Explanation:
1. Number of electrons

2. Number of protons

3. Identify the ion
An atom with 26 protons is iron, Fe.
A neutral atom of iron would have 26 electrons.
The ion has only 24 electrons, so it has lost two. The ion must have a charge of +2.
