A new sunscreen has been developed that is supposed to be more effective at preventing sunburn. 30 participants spray one arm with the new formula, and spray the other arm with the leading formula. After 4 hours in the sun, their skin is evaluated for any redness. What is the purpose of the experiment? Identify the independent variable. Identify the dependent variable. Describe the first group of people in the experiment. Describe the second group of people in the experiment. Identify two factors which are kept constant( same). Which group is the test group? Which group is used for comparison?

Answers

Answer 1

Answer:

Explanation:

This question appears incomplete but can however still b answered.

The purpose of the experiment is to test the effectiveness of the new sunscreen.

An independent variable is the variable that is changed (directly or indirectly) during the course of an experiment. The independent variable here are the sunscreen.

A dependent variable is the variable that is been tested in the course of the experiment. The dependent variable here is the redness of the skin.

The first group here (this could be in the missing part of the question, hence response not certain) is the control group. The control group consists of the arms sprayed with the leading/old sunscreen formula.

The second group is the test group. It consists of the arms sprayed with the new sunscreen formula.

The factors that are kept constant (or control variable) are the duration under the sun (4 hrs) and the participants' arms used.

The test group is the second group while the group used for comparison (to be sure the new sunscreen is more effective) is the first group.


Related Questions

The simple unit of a compound

Answers

Molecules are the simplest unit of a compound.

Answer:

the basic unit of an ionic compound is called a formula unit and the basic unit of a covalent compound is a molecule.

The value equal the sum of the protons and neutrons in the nucleus of an atom

Answers

The Atomic Number should be your answer, although I am not completely sure.

Question in picture below

Answers

Answer:

Models 1 and 2 would be in the same group.

Explanation:

They have the same amount of valence electrons. Valence electrons are electrons in the outermost electron cloud. This means they have the same properties, therefore are in the same Group on the periodic table.

Models 1 and 2 would be the same

Please help with my chemistry homework

Answers

Answer:

amu, atomic number, electrons, atomic mass

Explanation:

What affects the direction of the current

Answers

Answer:

direction of the wire moves in and the direction of magnetic field.

If you used a heat lamp instead of a flashlight, which penny would get the hottest?

Answers

A copper penny..............

The Hot-Wheel car was accelerating across the table at 0.25 meters per second squared (m/s^2) from an applied force of 10 N. What is the mass of the Hot Wheel car? *
40 grams
2.5 grams
0.025 grams
cannot be determined

Answers

Answer:

Explanation:

Consider the motion of a Hot Wheels car beginning from rest at an elevated position. The Hot Wheels car rolls down a hill and begins its motion across a level surface. Along the level surface, the Hot Wheels car collides with a box and skids to a stop over a given distance. How could work and energy be utilized to analyze the motion of the Hot Wheels car? Would the total mechanical energy of the Hot Wheels car be altered in the process of rolling down the incline or in the process of skidding to a stop? Or would the total mechanical energy of the Hot Wheels car merely be conserved during the entire motion?

Of course the answers to these questions begin by determining whether or not external forces are doing work upon the car. If external forces do work upon the car, the total mechanical energy of the car is not conserved; the initial amount of mechanical energy is not the same as the final amount of mechanical energy. On the other hand, if external forces do not do work upon the car, then the total mechanical energy is conserved; that is, mechanical energy is merely transformed from the form of potential energy to the form of kinetic energy while the total amount of the two forms remains unchanged.

While the Hot Wheels car moves along the incline, external forces do not do work upon it. This assumes that dissipative forces such as air resistance have a negligible affect on the car's motion. This is a reasonable assumption for the low speeds of the car and its streamline characteristics. Since external forces do not do work on the car, the total mechanical energy of the car is conserved while moving along the incline. As the work-energy bar charts in the animation below depict, energy is transformed from potential energy (the stored energy of position) to kinetic energy (the energy of motion). The car gains speed as it loses height. The bar chart also depicts the fact that the total amount of mechanical energy is always the same; when the two forms are added together, the sum is unchanging.

When the Hot Wheels car collides with the box and skids to a stop, external forces do a significant amount of work upon the car. The force of friction acts in the direction opposite the car's motion and thus does negative work upon the car. This negative works contributes to a loss in mechanical energy of the car. In fact, if 0.40 Joules of mechanical energy are lost, then -0.40 Joules of work are done upon the car. As this work is done, the mechanical energy of the car (in the form of kinetic energy) is transformed into non-mechanical forms of energy such as sound and heat.

why don't the praticles in a solid move past one another

Answers

Answer:

Particles in a solid object are super tight and close to eachother. They do not move past eachother because it is a solid, not a liquid or gas.

Explanation:

Solid – In a solid, the attractive forces keep the particles together tightly enough so that the particles do not move past each other. Their vibration is related to their kinetic energy. In the solid the particles vibrate in place.

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Are the effects of adding heat reversible

Answers

Answer:

yes they are

Explanation:

if you are heating up glass i believe not, unless you want to break the glass. Making glass go from high to low or low to high tempuatures quickly will cause it to break. How ever metal will be stronger as long as you dont bend it.

if i put a ice cube on a table what type of phase would occur
melting
freezing
condensation
evaporation

Answers

Answer:

melting

Explanation:

the ice would turn to water before it evaporated

M= 25.4 g
V= 12.2 mL
D=

Answers

Answer:

Explanation:

density = m/v

answer = 2.0819 g/ml

rounded (correct sig figs) = 2.08

Answer:

About 2.08 g/mL

Explanation:

25.4g ÷ 12.2 mL = 2.0819..... g/mL

About 2.08 g/mL

which sentece is a scentific statement

Answers

I theorize that this question will be deleted

How are electrons arranged around the nucleus of an atom​

Answers

Answer: electrons are arranged in shells around an atom's nucleus.

Explanation:

Electrons are arranged in shells around the nucleus. Electrons closest to the nucleus have the lowest energy. Electrons further away from the nucleus have a higher energy.

is mineral oil ionic or covalent

Answers

Answer:

Iconic

Explanation:

hope this helps :) x

When we convert one metric unit to another the conversion factor is always exactly equal to 1. true or false

Answers

Answer:

The answer is True.

Explanation:

You can use similar processes when converting from smaller to larger units. When converting a larger unit to a smaller one, you multiply; when you convert a smaller unit to a larger one, you divide.

use dimensional analysis to slove; a reasearcher is given 1.5 dry oz of a substance which he needs to evenly distribute over 10 vials. how many micrograms schools each vial contain? show all work.

Answers

Answer:

4.25248 x [tex]10^{6}[/tex] μg per vial

Explanation:

Conversion Factors

28.3495231 g = 1 dry oz

[tex]10^{6}[/tex] μg (micrograms) = 1 g

[(1.5 dry oz) x (28.3495231 g / 1 dry oz) x ([tex]10^{6}[/tex] μg / 1 g)] / 10 vials = 4,252,428.465 μg / vial

why do scientist study volcanos!!

Answers

Answer:

Volcanologists use many different kinds of tools including instruments that detect and record earthquakes (seismometers and seimographs), instruments that measure ground deformation (EDM, Leveling, GPS, tilt), instruments that detect and measure volcanic gases (COSPEC), instruments that determine how much lava is moving underground (VLF, EM-31), video and still cameras, infrared cameras, satellite imagers, webcams, etc!

Explanation:

I HOPE IT HELPED

Answer:

what the other guy said

Explanation:

Mrs. Rushing fills a balloon with hydrogen gas to demonstrate its ability to burn. Which combination could she
use to produce the hydrogen she needs?

NaOH and oil

Zn and KOH

H2SO, and CaCO

0 Mg and HCI

I’ll mark your reply if the answer was correct.

Answers

Answer:

Its D

Explanation:

I took the Unit Test on Edge

Answer:

D. Mg and HCl

In n=6 the correct sequence for filling of electron will be​

Answers

Answer:

If n=6, the correct sequence for filling of electrons will be ns→(n−2)f→(n−1)d→np

To calculate the relative age of rocks, geologists use the rate of radioactive decay of isotopes present in their samples. What is the term used for the original amount of
the elemental isotopes being investigated?
A rare earth isotopes
B. Son isotopes
C. daughter isotopes
D. parent isotopes

Answers

A

I have had this question!!
Hope this helps!!!

To calculate the relative age of rocks, geologists use the rate of radioactive decay of isotopes present in their samples. Rare earth isotopes the term used for the original amount of the elemental isotopes being investigated. Therefore, option A is correct.

What is isotope ?

Isotopes are different nuclear forms of the same element. They share the same atomic number and periodic table position, but their nucleon numbers differ due to different numbers of neutrons in their nuclei.

The rare-earth elements as a group have a high number of isotopes, ranging from 24 for scandium to 42 for cerium and averaging around 35 without counting nuclear isomers.

According to estimates, the total global reserve of rare earths is around 120 million metric tons. The majority of these reserves, estimated at 44 million metric tons, are in China.

Thus, option A is correct.

To learn more about the isotope, follow the link;

https://brainly.com/question/11680817

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A student pushes against a wall with 30 Newton’s of force and the wall does not move

Answers

Answer:

you can't go through a solid unless you broke the atoms in the wall

The standard unit of radiation related to biologic hazard is known as the .

Answers

Answer:

the standard unit of radiation related to biological hazards is known as the Roentgen.

Explanation:

A 32.5 g sample of metal X require 659 J of energy to heat it from 10°C to 77°C calculate the specific heat capacity of metal X. Round your answer to significant figures.

3.35 J/g °C
0.303 J/g °C
2170 J/g °C
169 J/g °C

Answers

Answer:

0.303 J/g°C.

Explanation:

From the question given above, the following data were obtained:

Mass (M) of metal = 32.5 g

Heat (Q) required = 659 J

Initial temperature (T1) = 10 °C

Final temperature (T2) = 77 °C

Specific heat capacity (C) of metal =.?

Next, we shall determine the change in temperature of the metal. This can be obtained as follow:

Initial temperature (T1) = 10 °C

Final temperature (T2) = 77 °C

Change in temperature (ΔT) =.?

Change in temperature (ΔT) = T2 – T1

Change in temperature (ΔT) = 77 – 10

Change in temperature (ΔT) = 67 °C

Finally, we shall determine the specific heat capacity of the metal as follow:

Mass (M) of metal = 32.5 g

Heat (Q) required = 659 J

Change in temperature (ΔT) = 67 °C

Specific heat capacity (C) of metal =.?

Q = MCΔT

659 = 32.5 × C × 67

659 = 2177.5 × C

Divide both side by 2177.5

C = 659/2177.5

C = 0.303 J/g°C

Therefore, the specific heat capacity of the metal is 0.303 J/g°C.

can protons neutrons and electrons be found on the ptoe?​

Answers

The number of electrons in a neutral atom is equal to the number of protons. The mass number of the atom (M) is equal to the sum of the number of protons and neutrons in the nucleus. The number of neutrons is equal to the difference between the mass number of the atom (M) and the atomic number (Z).


Protons, neutrons, and electrons: Both protons and neutrons have a mass of 1 amu and are found in the nucleus. However, protons have a charge of +1, and neutrons are uncharged. Electrons have a mass of approximately 0 amu, orbit the nucleus, and have a charge of -1.

If you add or subtract a proton from the nucleus, you create a new element. If you add or subtract a neutron from the nucleus, you create a new isotope of the same element you started with. In a neutral atom, the number of positively charged protons in the nucleus is equal to the number of orbiting electrons.

How long will it take a piece of strontium-90 (produced in a nuclear test blast) weighing exactly 1000.0 g to be
reduced to 15.625 g? The half-life of strontium 90 is 28.8 years,

Answers

Answer:

Time taken 172.8 years

Explanation:

Given data:

Total amount of strontium-90 = 1000.0 g

Amount left = 15.625 g

Half life of strontium = 28.8 years

Time taken = ?

Solution:

Number of half lives:

At time zero = 1000.0 g

At first half life = 1000.0g/2 = 500 g

At second half life = 500 g/2 = 250 g

At third half life = 250 g/ 2 = 125 g

At 4th half life = 125 g/ 2= 62.5 g

At 5th half life = 62.5 g/2 = 31.25 g

At 6th half life = 31.25 g / 2 = 15.625 g

Time taken:

Time taken = number of half lives × half life

Time taken = 6×28.8 years

Time taken = 172.8 years

This HAS to be an answer for second graders


Where do different kinds of apples come from?

Answers

Different kinds of apples come from when a tree branch acts a little differently than the rest. They might taste different or be more red. This is caused by genetic mutations

Wish of the following BEST describes an orbital?

a
According to the Bohr model of the atom, it is a three dimensional region of space where there is a 90% probability of finding a neutron at any given moment in time.
b
According to the Bohr model of the atom, it is a three dimensional region of space where electrons are constantly found.
c
According to the quantum mechanical model of the atom, it is a three dimensional region of space where protons are constantly found
d
According to the quantum mechanical model of the atom, it is a three dimensional region of space where there is a 90% probability of finding an electron at any given moment in time.

Answers

Answer:d

b/c the bohr atomic model say that the electron are present in the orbits where the modern physics suggests that according to hisenberg uncertainity principle u cannot locate an electron but can find its maximum probibility in a given region and that is named as orbital

The statement best describes an orbital is according to the quantum mechanical model of the atom, it is a three dimensional region of space where there is a 90% probability of finding an electron at any given moment in time. Therefore, option D is correct.

What the quantum mechanical model of the atom ?

The quantum mechanical model of atoms describes the three-dimensional position of the electron in a probabilistic manner using a mathematical function known as a wave function, which is frequently denoted as. Orbitals are another name for atomic wavefunctions.

The quantum mechanical model determines the allowed energies of an electron and the likelihood of finding the electron in different locations around the nucleus.

Electrons in the same atom with the same principal quantum number (n) or principal energy level are said to occupy an electron shell of the atom in the quantum-mechanical model of an atom. Orbitals are regions of space where electrons are likely to be found.

Thus, option D is correct.

To learn more about the quantum mechanical model of the atom, follow the link;

https://brainly.com/question/3453444

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A student estimates that 27 students will attend this month's
Science Club meeting 34 students attend. What was the
student's percent error?

Answers

Answer:

I think 20.58 so 21%?

Explanation:

describe how electrical energy can be transformed into mechanical energy within a magnetic field.

Answers

Answer:

this is the answer to your question bro or sis

Changing a solid to a liquid to a gas is changing the
matter.
*
Your answer

Answers

Answer:

i could help you can you explain more plzzzzzz i really need points

Explanation:

Answer:

It is changing the state of matter.

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