A ecosystem is SUSTAINABLE if it can continue to function over long periods of time.
Many species of plants can absorb heavy metals: those with atomic number greater than 20.
Some are essential for plant growth. These include
Mg, Mn, Fe, Ni, Cu, Zn, and Mo
Plants can absorb other heavy metals, but we don’t know their biological function. Among these are:
Co, Se, Cr, Cd, Ag, Hg, and Pb
Explanation:
When fluorine gas reacts with calcium metal at high temperatures then it results into the formation of calcium fluoride.
Since, calcium has 2 extra electrons as its electronic distribution is 2, 8, 8, 2. Whereas each fluorine atom needs one electron to complete its octet.
Therefore, the chemical reaction equation will be as follows.
Answer:
14 OH⁻(aq) + 2 Cr³⁺(aq) = Cr₂O₇²⁻(aq) + 7 H₂O(l) + 6 e⁻
Explanation:
In order to balance a half-reaction we use the ion-electron method.
Step 1: Write the half-reaction
Cr³⁺(aq) = Cr₂O₇²⁻(aq)
Step 2: Perform the mass balance, adding H₂O(l) and OH⁻(aq) where appropriate
14 OH⁻(aq) + 2 Cr³⁺(aq) = Cr₂O₇²⁻(aq) + 7 H₂O(l)
Step 3: Perform the electric balance, adding electrons where appropriate
14 OH⁻(aq) + 2 Cr³⁺(aq) = Cr₂O₇²⁻(aq) + 7 H₂O(l) + 6 e⁻