I think A. o2 is oxygen, h202 is a clear liquid like bleach, And H20 is water lol :P
The correct answer is D. Assent of the child and permission of both parents are required.
Explanation:
In any research study, it is required to ask for the assent of the participants, no matter if the risk is low, which is established by the Institutional Review Board or IRB that regulates ethics in research. This implies in the case presented, the assent of the child is necessary, especially because a medical procedure (additional bone marrow aspirates) will be performed, and this is related to risks.
Besides this, if the participant is a minor the permission of both parents or the legal is needed as the child might not have the maturity to decide whether to participate in the research study. Thus, the requirements are " Assent of the child and permission of both parents are required".
The environment affects natural selection. Speices need to adapt to changes in environmnet. The weaker organisms which fail to adapt to environment perish while the stronger ones who adapt to the environment survive. This is how environment affects natural selection.
Answer: option 1. i and ii
Explanation:
Answer:
39.7 %
Explanation:
magnesium + oxygen ⟶ magnesium oxide
10.57 g 6.96 g 17.53 g
According to the <em>Law of Conservation of Mass</em>, the mass of the product must equal the total mass of the reactants.
Mass of MgO = 10.57 + 6.96
Mass of MgO = 17.53 g
The formula for mass percent is
% by mass = Mass of component/Total mass × 100 %
In this case,
% O = mass of O/mass of MgO × 100 %
Mass of O = 6.96 g
Mass of MgO = 17.53 g
% O = 6.96/17.53 × 100
% O = 0.3970 × 100
% O = 39.7 %