H2O became a vapor when heated because thats the only one that can go back to its normal state, which is what a physical change is.
Answer:
Pangaea
Explanation:
About 300 Million Years Ago, Earth Didn't Have Seven Continents But Instead Earth Had One Massive Super continent Called Pangaea.
Answer:
1. Temperature is the measurement of how hot or cold something is.
agree
2. When something heats up, new energy is created, and when something cools down, energy is destroyed.
disagree
3.When something heats up, it moves faster, and when something cools down, it moves slower.
agree
4. Hotter things have more energy than colder things.
agree
The correct answer is D. melting the solid.
Answer:
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- <em>The halogens posses </em><u><em>seven </em></u><em>valence electrons</em>
Explanation:
- <em>Valence electrons </em>are the electrons in the outermost orbitals of the atoms, which are the orbitals with the highest main energy level (principal quantum number).
- Halogens are the elements of the group 17 of the periodic table: F, Cl, Br, I, At.
- You can tell the number of valence electrons of the representative elements from the number of the group to which they belong. For the representative elements, the number of valence electrons equal the unit digit of the group number.
This table summarizes it:
Group number number of valence electrons
1 1
2 2
13 3
14 4
15 5
16 6
17 7
18 8
- So, in conclusion, <em>the halogens possess 7 valence electrons.</em>
