Answer:
This question will be answered based on general understanding of how a controlled experiment should be:
The answer is: We must make sure we are testing/changing only one variable, and controling others
Explanation:
A controlled experiment is an experiment in which the independent variable is changed for a particular group called the EXPERIMENTAL group and unchanged for another group called the CONTROL group.
In a controlled experiment, only one variable should be tested while the others should be kept constant in order to have an effective result or outcome. This is the case in this question, the type of music or soil should be unchanged for each plant because the experimenter must make sure that he/she is testing/changing only one variable, and controling others.
Answer:
320 g
Step-by-step explanation:
The half-life of Co-63 (5.3 yr) is the time it takes for half of it to decay.
After one half-life, half (50 %) of the original amount will remain.
After a second half-life, half of that amount (25 %) will remain, and so on.
We can construct a table as follows:
No. of Fraction Mass
half-lives t/yr Remaining Remaining/g
0 0 1
1 5.3 ½
2 10.6 ¼
3 15.9 ⅛ 40.0
4 21.2 ¹/₁₆
We see that 40.0 g remain after three half-lives.
This is one-eighth of the original mass.
The mass of the original sample was 8 × 40 g = 320 g
Answer:
1. C
2. C
3. A
4. C
5. True
6. C
Explanation:
1. C The answer is conduction because the heat was transferred through direct contact.
2. C The answer convection because the heat was transferred through a medium (liquid/gas).
3. A The answer is conduction because the heat was transferred through direct contact.
4. C The answer is radiation because the heat was transferred through thermal emission.
5. True. This is because the air that is warmed rises, causing the cool air to replace it. You can picture it like the scenario in question 2.
6. C
The molarity of this should be around 0.846
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Formula: M= mols/liters
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So… M= 11.6/13.7⇒ 0.846
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