There are 4 things that are evidence of a chemical change.
1)Change in color
2)Change in shape (gas being let out)
3)Change in temperature
4)Change in smell
Burning wood is a chemical change because it has a change in color, and shape.
Answer:
Eutrophication is the enrichment of a body of water with excessive nutrients (nitrogen and phosphorus), which causes algal growth and subsequent decline of dissolved oxygen after decomposition.
<span>Xe = VIII = 8 valence electrons
F = VII = 4 (7 ve) = 28 valence electrons</span>
total ve = 8 + 28 = 36 ve
<span>36 - 4(2) = 28 ve
(there are 2 electrons in each bond x 4 bonds)</span>
<span>28 - 4(6) = 4
(We assign the remaining electrons to F atoms)</span>
<span>4 - 2(2) = 0
(Therefore 4 electrons left => we have 2 lone pairs)</span>
The steric number = No. of
σ bonds + #lone pairs
= 4 σ bonds + 2 lone pairs
= 6 => d²sp³ (6 hybrid orbitals)
<span>4 bonds + 2 lone pairs
=> square planar</span>
Answer:
yes
Explanation:
SI unit of mass is kilogram.