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Afina-wow [57]
3 years ago
7

Yasir wants to determine if there is a relationship between room color and sleep. Based on his research, Yasir makes an educated

guess that people fall asleep more quickly in a room painted blue than in a room painted yellow. He asks several people which color they like better—yellow or blue—and uses their responses to determine if his educated guess was correct.
What is missing from Yasir's scientific investigation?

A testable hypothesis that is based on research
An experiment that directly tests the hypothesis
Variables to be tested by an experiment
Research on the topic to see what others have learned
Chemistry
1 answer:
Helen [10]3 years ago
8 0

Answer: B. An experiment that directly tests the hypothesis

Explanation:

Yasir didn’t really test his experiment he only ask people for the opinion on which color they like so he forget to actually do the experiment therefore the answer is b.

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How can endangered species be saved ?
labwork [276]

Answer:

There are lots of methods.

Explanation:

Usually, animals like pandas live a shorter lifespan in the wild than in captivity. A little fact, there is only one brown panda in the entire world, so it would be very, very rare to see one. The Smithsonian National Zoo, for example, are working to protect pandas, as well as other species.

5 0
3 years ago
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How many phosphorous atoms are found in three molecules of magnesium phosphate, 3Mg3(PO4)2?
aleksandr82 [10.1K]

Answer: Option (d) is the correct answer.

Explanation:

Since the given formula is 3Mg_{3}(PO_{4})_{2}. According to cross method formula, magnesium has +2 charge so, PO_{4} is multiplied by 2.

Thus, 1 molecule of magnesium phosphate will contain 2 atoms of phosphorus.

Therefore, three molecules of magnesium phosphate contains following number of atoms.

  • Mg = 9
  • P = 6
  • O = 24

Hence, we can conclude that there are 6 atoms of phosphorus in three molecules of magnesium phosphate, 3Mg_{3}(PO_{4})_{2}.

4 0
4 years ago
Which of the following statements about enthalpy is true?
Evgesh-ka [11]

Answer:    A chemical process must occur and then changes between the state of the reactants and the state of the products can be determined

Explanation:  Enthalpy represents the sum of the energy of the system with the product of the pressure and volume of that system. As a thermodynamic property, it expresses the ability to release heat from the system. In fact, enthalpy  tells us how much heat and work has changed during the chemical reaction under constant pressure. When measuring, measurements of the difference in enthalpy between the two states of the system is performed, before and after the chemical reaction, since total enthalpy can not be measured. This measurement of the enthalpy change can tell us, for example, whether the heat was released from the system during the reaction, or the system absorbed the heat.

7 0
3 years ago
Which of the following is likely to have the lowest viscosity? hot oil room temperature oil room temperature water below room te
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Viscosity, is a state of matter where it resists flow or may be in thick semifluid form because of friction acting inside the matter.In this case, hot oil room temperature would lessen the viscosity of the oil (animal oil). Thank you for your question. Please don't hesitate to ask in Brainly your queries. 
4 0
4 years ago
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Which list represents the classification of the elements nitrogen, neon, magnesium, and silicon, respectively?
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The question is incomplete. Complete question is:
Which list represents the classification of the elements nitrogen, neon, magnesium, and silicon, respectively?
(1) metal, metalloid, nonmetal, noble gas
(2) nonmetal, noble gas, metal, metalloid
(3) nonmetal, metalloid, noble gas, metal
(4) noble gas, metal, metalloid, nonmetal
.................................................................................................................

Answer: The correct answer is option 2) nonmetal, noble gas, metal, metalloid

Reason: 
1) Non-metal are bad conductors of electricity. Also non-metal are electronegative in nature. Hence, among the provided elements, nitrogen satisfied the criteria. Hence, it is a non-metal.

2) Noble gas are the elements which have completely filled outermost shell. Hence, among the provided elements, Neon satisfied the criteria.

3) Metal are good conductors of electricity. Also metal are electropositive in nature. Hence, among the provided elements, magnesium satisfied the criteria. Hence, it is a metal.

4) Metalloid have conductivity better than non-metals but poor than conductors. Hence, among the provided elements, Silicon satisfied the criteria. Hence, it is a metalloid.
6 0
4 years ago
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