B) Drug
C) Medicine
D) Screening Tool
Ohp xD nvm, the answer is A !
During the test trial, the sugar pill given to the control group is called a placebo. Therefore, the correct option is A. Placebo
A placebo is any drug or a treatment with no active substances, for example a sugar pill.
During clinical trials, usually one group takes the actual drug while the other group takes the placebo without being aware of it.
Placebo is an inactive treatment given to a group of people that is made to look like the real drug, but in reality it simply makes the patient believe they're being treated with the drug and that the drug will help them relieve from the symptoms.
By comparing the results from the two groups, this method helps in analyzing the accurate effects of the drug on the patients and helps in proving that it was the drug that actually treated the symptom and that the treatment did not occur by chance or just a mere belief of the patient thinking they will get better because they're being treated.
This approach helps reduce bias and ensures that the trial's results are more accurate and reliable.
So, the sugar pill given to the control group is called a placebo. Therefore, the correct option is A. Placebo
To learn more about placebo, click on
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The model most likely represents a reaction which
Select one:
a. takes place when atoms combine
b. takes place when atoms become inactive
c. does not produce energy in the sun
d. does not produce energy in nuclear power plants
Answer:
Correct answer is option C (does not produce energy in the sun )
Explanation:
Fusion:
When two light nuclei combined to form a heavy nucleus that time large amount of energy is emitted and this reaction is known as fusion reaction.
In sun energy is produced due to fusion reaction but in this model atom1 is splitting in two light nuclei with emission of energy this type of reaction is known as fission reaction. This type of reaction is used to produce energy in nuclear power plant.So option D is not correct and it does not produce energy in the sun so option C is correct because this is fission reaction and in sun energy is produce due to fusion reaction.
Answer:
Correct answer is a. Ag(s) reacts spontaneously with 1M H+(aq).
Explanation:
A charasteristic of metals is that they lose easily electrons, cations tends to gain electrons to react and anions tends to lose or share electrons to react.
If you want to make a chemical reaction you must to mix a reagent that tends to lose electrons with other that tends to gain them.
In the statement (a) we have a metal that loses electrons and a cation that can obtain them, so is the right answer.
note that the other optios have :
b) Metal with metal cation, not react beacause left a medium of reaction.
c) Both loses electrons
d) Both tends to gain electrons.
(2) selenium (4) sodium
Selenium has the greatest density at STP.
According to Ideal gas equation,
P V = n R T
where;
n = m/M
Therefore,
P V = m R T / M
Rearranging,
P M = (m/V) R T
Also,
m/V = density = d
So,
P M = d R T
Solving for density,
d = P M / R T
According to this equation density is directly proportional to Molar mass of a substance. Hence, the Atomic masses of given compounds are listed below,
Scandium = 44.96 g.mol⁻¹
Selenium = 78.97 g.mol⁻¹
Silicon = 28.09 g.mol⁻¹
Sodium = 22.99 g.mol⁻¹
Therefore, selenium having the greatest Atomic Mass will have the greatest density. The densities of given elements are as follow;
Scandium = 2.98 g.cm⁻³
Selenium = 4.81 g.cm⁻³
Silicon = 2.33 g.cm⁻³
Sodium = 0.96 g.cm⁻³
has the greatest density at STP.
Further Explanation:
Ideal gas law is the equation of state for any hypothetical gas. The expression for the ideal gas equation is as follows:
…… (1)
Here,
P is the pressure.
V is the volume.
T is the absolute temperature.
n is the number of moles.
R is the universal gas constant.
The formula to calculate the number of moles is as follows:
...... (2)
Here,
n is the number of moles.
m is the mass.
M is the molar mass.
Substitute the value of n from equation (2) in equation (1).
…… (3)
Rearrange equation (3) as follows:
…… (4)
The formula to calculate density is as follows:
...... (5)
Here,
is the density.
m is the mass.
V is the volume.
Substitute equation (5) in equation (4).
…… (6)
Rearrange equation (6) to calculate the density.
...... (7)
At STP, T and P remain constant, R is already a constant. So according to equation (7), density of substance is directly proportional to the molar mass of the substance.
The molar mass of scandium is 44.96 g/mol.
The molar mass of selenium is 78.97 g/mol.
The molar mass of silicon is 28.09 g/mol.
The molar mass of sodium is 22.99 g/mol.
The molar mass of selenium is the highest among the given elements so its density will be the greatest.
Learn more:
1. Which statement is true for Boyle’s law: brainly.com/question/1158880
2. Calculation of volume of gas: brainly.com/question/3636135
Answer details:
Grade: Senior School
Subject: Chemistry
Chapter: Ideal gas equation
Keywords: P, V, n, R, T, ideal gas, pressure, volume, selenium, sodium, scandium, silicon, 22.99 g/mol, 78.97 g/mol, 28.09 g/mol, 44.96 g/mol, density, molar mass.
The bouncing back of light waves observed when light waves hit ice and most of them bounce off and radiate back into space is called reflection.
Light waves are a form of waves which produces visible sensitization of the eyes
Light waves have properties of waves such as:
When light waves hit ice, most of them bounce off and radiate back into space.
This property of light waves is known as reflection.
Learn more about reflection of light waves at: brainly.com/question/1191238
When light waves hit ice, most of them bounce off and radiate back into space, hence, ice is best described as a reflective surface.
A reflective surface is one which can cause incident light to bounce back (reflection).
According to this question, when light waves hit ice, most of them bounce off and radiate back into space. This means that most of the incident lightreflects off the ice surface.
Therefore, the ice surface is best described as a reflective surface.
Learn more about reflection at: brainly.com/question/8553652