<u>c.</u> 12. preparing data tables and gathering safety equipment
<u>b.</u> 13. reading all instructions before beginning a science lab
<u>a.</u> 14. recognizing what a picture of a hand means
<u>e.</u> 15. wiping your work area with a wet paper towel
<u>d.</u> 16. wearing goggles and an apron
Answer:
I believe the answer is "b". "During the experiment, the scientist has only one element, or variable, that is changed to test the hypothesis."
Explanation:
I remember from last year but I'm not totally sure. Good luck!
Answer:
oxygen is limiting reactant
Explanation:
Given data:
Mass of hydrogen = 16.7 g
Mass of oxygen = 15.4 g
Limiting reactant = ?
Solution:
Chemical equation:
2H₂ + O₂ → 2H₂O
Number of moles of hydrogen:
Number of moles = mass/ molar mass
Number of moles = 16.7 g/ 2 g/mol
Number of moles = 8.35 mol
Number of moles of oxygen:
Number of moles = mass/ molar mass
Number of moles = 15.4 g/ 32 g/mol
Number of moles = 0.48 mol
Now we will compare the moles of both reactant with product,
H₂ : H₂O
2 : 2
8.35 : 8.35
O₂ : H₂O
1 : 2
0.48 : 2×0.48 = 0.96 mol
The number of moles of water produced by oxygen are less so it will limiting reactant.
Answer: Option (a) is the correct answer.
Explanation:
Transmutation involves the conversion of one chemical element into another chemical element. This change occurs when an element or isotope passes through a number of reactions. It is a natural process and happens when there is a radioactive decay.
Hence, it is also a nuclear change as it occurs when there is a change in the nucleus of an atom. As this change can be due to the nuclear decay so as a result there will be some change in energy also. It is the process where one element converts into another using bombardment with high energy particles.
Thus, we can conclude that transmutation involves is a nuclear change.
