D is a correct Lewis Dot structure. Nitrogen has 4 valence electrons.
The reaction formula of this is C3H8 + 5O2 --> 3CO2 + 4H2O. The ratio of mole number of C3H8 and O2 is 1:5. 0.025g equals to 0.025/44.1=0.00057 mole. So the mass of O2 is 0.00057*5*32=0.0912 g.
let me know when u find out plz because i would like to know as well its one of my chemistry qustions in an assiment. :)
Answer:
A scientific question to be asked is; <em>What is the average speed of the toy car?</em>
Explanation:
A scientific question is a question which is well defined, the values in the question can be measured, and the inputs and outputs related to the question are controllable
The parameters measured in the experiment are;
The time elapsed during the movement of the car, <em>Δt</em>
The distance the car moves, <em>d</em>
From the obtained measurements, the value can be calculated is the average speed of the toy car as follows;

Therefore, a scientific question to be asked that will be answered by doing the experiment is; What is the average speed of the toy car?
Answer:
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Explanation: