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4 years ago

18. When we conduct an experiment the condition we are investigating the one thing we want to know about is called the

Chemistry

2 answers:

umka2103 [35]4 years ago

8 0

18. When we conduct an experiment the condition we are investigating the one thing we want to know about is called the:

b. hypothesis - we are conducting the experiment in order to validate or invalidate the hypothesis

19. The group of experimental subjects that is left “natural” or left unchanged is called the:

a. control group - we need to have a reference point for our experiment to check if something has changed, how much have been changed or if have not changed at all.

20.The group of experimental subjects that has the one condition changed is the:

b.experimental group - on this grump we make changes and compare the results with the control group

21. When the experiment is complete the researcher:

c. analyzes the data and comes to a conclusion - after experiments the data are analyzed to see if the hypothesis is proved of not.

Neporo4naja [7]4 years ago

3 0

Answer:

The correct answer will be option-

18. option-B hypothesis

19. option- A control group

20. option- B experimental group

21. option- C analyzes the data and comes to a conclusion

Explanation:

A scientific experiment is a systematic approach to understand and explain the natural events which include various sequential steps.

In question 18, the experiment is conducted to test the well-educated guess based on the background research which explains the phenomenon to a limited extent. This proposed statement is known as the hypothesis and is the answer.

in question 19, the sample group which is left undisturbed or in which the variable to be tested is missing is known as the control group and thus is the correct answer.

in question 20, the sample group in which the independent variable is changed which influence the dependent variable is known as the experimental group.

In question 21, after the experiment, the next step will be the analysis of the collected data from which the conclusion is drawn and is the correct answer.

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3 years ago

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Electrons in an atom are contained in specific energy levels that are different distances from the nucleus.
Within each energy level is a volume of space where specific electrons are likely to be located, called orbitals. Orbitals are of different shapes, denoted by a letter (s, p, d, f, g).
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3 years ago

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3 years ago

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A solution contains one or more of the following ions: Ag+, Ca2+, and Co2+. Lithium bromide is added to the solution and no prec

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<h3>Answer:</h3>

#1. Ca²⁺

# 2. Ca²⁺(aq) + SO₃²⁻(aq) → CaSO₄(s)

#3. 3Ag⁺(aq) + PO₄³⁻(aq) → Ag₃PO₄(s)

<h3>Explanation:</h3>

The question above concerns solubility of salts or ions in water.

The solution given contains Ag+, Ca2+, and Co2+ ions.

In the first case, when Lithium bromide is added to the solution, there is no white precipitate formed.
In the second case, the addition of Lithium sulfate results in the formation of a precipitate because of the Ca²⁺ in the solution combined with the SO₃²⁻ from lithium sulfate to form an insoluble CaSO₄.

The net ionic equation for the reaction is;

Ca²⁺(aq) + SO₃²⁻(aq) → CaSO₄(s)

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In the third case, the addition of Lithium phosphate results in the formation of a precipitate because Ag⁺ ions in the solution combine with phosphate ions ( PO₄³⁻) from lithium phosphate to form an insoluble salt, Ag₃PO₄.

The net ionic equation for the reaction is;

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