The answer is D, alters the test variable, and observes the effects on other outcome variables.
The answer is: It expands when it freezes.
When molecule frezes, it lose energy. When molecules are far apart, it means the volume is greater and it expands.
For example, ice expands when water is freezing.
Hydrogen bond is an electrostatic attraction between two polar groups that occurs when a hydrogen atom (H), covalently bound to a highly electronegative atom such as flourine (F), oxygen (O) and nitrogen (N) atoms.
His work foreshadowed the periodic table. He tried organizing elements into triads, a set of 3 elements with similar properties. In each triad the mean of the lightest and heaviest atomic weight equaled to approximately the atomic weight of the middle element.
Answer:
Br - C ≡ N
Explanation:
To draw the Lewis line-bond structure we need to bear in mind the octet rule, which states that in order to gain stability each <em>atom tends to share electrons until it has 8 electrons in its valence shell</em>.
- C has 4 e⁻ in its valence shell so it will form 4 covalent bonds.
- Br has 7 e⁻ in its valence shell so it will form 1 covalent bond.
- N has 5 e⁻ in its valence shell so it will form 3 covalent bonds.
The most stable structure that respects these premises is:
Br - C ≡ N
It does not have any H atom.
