The following are the statements, which indicates that the fossil record suggests about evolution on Earth:
1. Humans have only recently existed on Earth.
2. The organisms originally lived only in Earth's water.
3. The plants did not have flowers when dinosaurs existed.
The fossil remains have been discovered in the rocks of all the ages. The simplest organisms fossils are witnessed in the oldest rocks, and the fossils of more composite species are found in the newest rocks. This supports the theory of evolution suggested by Darwin, according to which the simple life forms slowly gets evolved into more composite ones.
Just choice D.
If you find the number of atoms of each element, you will find that only choice D has the same amounts on each side of the equation.
Answer: The given statement is true.
Explanation:
Water is a natural resource present in the nature and it is very precious as life without it is impossible.
So, when we unnecessarily use water then it means we are wasting a natural resource that cannot be reproduced again by human beings.
Therefore, more we are able to conserve water more we can protect other human life's and environment also.
If there is shortage of water then its prices will go high and hence we need to pay more for it.
Thus, we can conclude that the statement conserving water can save money while protecting the environment, is true.
Answer:
ΔG° = -533.64 kJ
Explanation:
Let's consider the following reaction.
Hg₂Cl₂(s) ⇄ Hg₂²⁺(aq) + 2 Cl⁻(aq)
The standard Gibbs free energy (ΔG°) can be calculated using the following expression:
ΔG° = ∑np × ΔG°f(products) - ∑nr × ΔG°f(reactants)
where,
ni are the moles of reactants and products
ΔG°f(i) are the standard Gibbs free energies of formation of reactants and products
ΔG° = 1 mol × ΔG°f(Hg₂²⁺) + 2 mol × ΔG°f(Cl⁻) - 1 mol × ΔG°f(Hg₂Cl₂)
ΔG° = 1 mol × 148.85 kJ/mol + 2 mol × (-182.43 kJ/mol) - 1 mol × (-317.63 kJ/mol)
ΔG° = -533.64 kJ
When a radioactive isotope releases an alpha particle, the atomic number of the atom is decreased by four.
So, the correct answer is B.
Hope this helps,
Davinia.
