Answer: B
Explanation: to have a control, and many samples to investigate and cover the differences and anseretics.
In a survey that asked about alcohol use in high school students , the important measure for controlling bias is "Getting a random sample from all grade levels".
What is alcohol?A chemical compound is found in alcoholic beverages like beer, wine, as well as liquor. Several medicines, mouthwashes, home items, as well as essential oils contain it.
In a survey that asked about alcohol use in high school students , the important measure for controlling bias is "Getting a random sample from all grade levels".
Therefore, the correct answer will be option (B).
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calculate and compare the chemical energy of coal to its gravitational potential energy. Burning 1 kg of coal releases about 3 million joules of energy. if you could use all of the chemical energy to lift another kilogram of coal, how could you lift it?
Answer:
Explanation:
chemical energy of 1 kg coal is 3 million joules .
If this energy is used to lift one kg of coal , let height attained be h
chemical energy = gravitational energy of 1 kg of coal
3 x 10⁶ = m g h = 1 x 10 x h
h = 3 x 10⁵ m
= 300 x 10³ m
= 300 km .
i kg coal can be lifted by height of 300 km .
how does the difference in ignition temperature of fuel affect their use
#urgent ...pls
Answer:
Nuclear Fusion
The binding energy per nucleon curve (Figure 43.1) peaks at a nucleon number of about 56. This means that nuclei having A = 56 are more tightly bound than either less massive or more massive nuclei. Nuclear fission of nuclei with A ≈ 240 releases energy because the fragments have mass numbers closer to the A = 56 peak and are therefore more tightly bound. Nuclear reactions between light nuclei that produce more massive and more tightly bound nuclei also release energy.
please solve this problem
Explanation:
ans b hcl and ccl4
both these compounds are formed by sharing of electrons......
State and explain modern periodic table. ⊕⊕
Explanation:
the physical and chemical properties of an element are periodic functions of their atomic number.
Answer:modern periodic table is published by Henry Moseley and he believes that ' properties of an elements are periodic function of the atomic number' and he classify the periodic table by groups and perieods so in the modern periodic table there are seven periods and eighteen groups.
Which two characteristics affect ocean water’s temperature?
salinity and waves?
location and depth?
mass and salinity ?
waves and location??
Answer:
The correct answer is location and depth
Explanation:
Correct on edge 2020
Answer:
B.) Location and Depth
2. Calculate how far light travels in 8.64 x
104 seconds. (Hint: The speed of light is
about 3,0 x 100 m/s.)
PEARSON
which product of petroleum is normally used as fuel in cars and light vehicles
Answer:
mostly gasoline in cars nowadays
Some people rinse their freshly shampooed hair in diluted lemon juice or vinegar. Why is this done?
Answer:
the citric acid in lemon juice is a natural bleach, or oxidizing agent. It whitens hair by chemically reducing your hair's color pigment, or melanin. When exposed to the sun, the citric acid accelerates the bleaching process
The process of rinsing freshly shampooed hair in diluted lemon juice or vinegar significantly shines hair through the process of chemical reduction of hair color pigment that is known as Melanin.
What is the function of diluted lemon juice on hair?The function of diluted lemon juice is that the lemon juice remarkably consists the citric acid which is known as a natural bleach. It works as an oxidizing agent when it reacts with hair that contains a dark-colored pigment.
After performing the overall process, when your hair is directly exposed to the sun, it significantly enhances the process of bleaching which gives more shine to the hair. Vinegar balances the pH of your hair cleans out the hair shaft, and gives it a shine.
Therefore, the process of rinsing freshly shampooed hair in diluted lemon juice or vinegar significantly shines hair through the process of chemical reduction of hair color pigment that is known as Melanin.
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what evidence is there that all state of matter have mass
Answer:
Matter is the "stuff" that makes up the universe everything that takes up space and has mass is matter.
All matter is made up of atoms, which are in turn made up of protons, neutrons and electrons
Matter itself must have mass irrespective of its state.
Matter is anything that has mass and occupy space. Matter exists in three states;
Solid Liquid GasIn all these states of matter, matter is made up of "stuff". For instance, if a solid, liquid or gas is introduced into an empty bag attached to a scale, the bag will move downwards and the scale will record an increase in mass.
This shows that matter in solid, liquid or gaseous state all have mass.
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The density of gold is 19.3 g/cm3 and the density of lead is 11.4 g/cm3. If you have 5 grams of gold and 5 grams of lead, which will have the greater volume?
Given :
The density of gold is [tex]19.3 \ g/cm^3[/tex] and the density of lead is [tex]11.4\ g/cm^3[/tex] respectively .
To Find :
Which have greater volume .
Solution :
We know , density is given by :
[tex]\rho=\dfrac{mass}{volume}[/tex]
Now , volume of 5 gm gold .
[tex]Volume=\dfrac{mass}{\rho}\\\\Volume =\dfrac{5}{19.3}\ cm^3\\\\Volume =0.26\ cm^3[/tex]
Also , volume of 5 gm lead .
[tex]Volume=\dfrac{mass}{\rho}\\\\Volume =\dfrac{5}{11.4}\ cm^3\\\\Volume =0.44\ cm^3[/tex]
Therefore , volume of lead will be greater than gold.
Hence , this is the required solution .
You are starting with 2 pounds of 30% acetic acid solution. You want to dilute
(water down) to make it a 15% solution. How many pounds of water do you have
to add? (HINT: calculate mass of solute in the 30% solution first)*
Answer:
The mass of water to be added is 2 pounds
Explanation:
The given parameters are;
The mass of the given solution = 2 pounds
The concentration of the given solution = 30%
The desired concentration of the solution = 15%
The mass, m of the acetic acid in the given solution = 30% × 2 pounds
m = 30/100 × 2 pounds = 0.6 pounds
To make a 15% acetic acid solution of acetic acid, the mass X of the required volume, is given as follows;
15% of X = 0.6 pounds
15/100 × X = 3/20 × 0.6 pounds
∴ The mass of the solution required X = 0.6 × 20/3 = 4 pounds
The mass of the solution that will contain 0.6 pounds of acetic acid giving a 15% acetic acid solution is 4 pounds
Therefore, the mass of water to be added to the original solution to make the a 15% acetic acid solution is 2 pounds.
Which state of matter can change both shape and volume?
O solid
O liquid
O gas
Answer:
Gas
Explanation:
Gasses will fill the shape whatever container they are in and can be compressed down into smaller volumes quite easily.
Solids have a definite shape and volume
liquids have an indefinite shape but a definite volume
Heat is the movement of thermal energy from one place to another. True or False
Answer:
True
Explanation:
Heat is the transfer of thermal energy from a system to its surroundings or from one object to another. This transfer of energy is from the object at a higher temperature to the object at a lower temperature.
Which of these is a sign of salinization in crop plants?
A. Yellowing of leaves
B. Wilting of seedlings
C. Dead patches on leaves
D. Enlarged seedlings
Answer:
The correct answer I think is Wilting of Seeds
Explanation:
salinization is when the water evaporates and leaves behind the salt in the water. Which causes the seed to whither because salt sits in its roots, and leaves no way for any more water to get in. So it makes it hard for seedling so get water.
I think that is correct! Hope its right
A sign of salinization in crop plants is Wilting of seedlings. Thus the correct option is B.
What is salinization ?Increased salt percentage in the soil is known as salinization, and it is brought on by soluble substances in the water supply. The land may be flooded by seawater or saline groundwater flowing through the soil downward, depending on the source of the water.
Due to the poor plant growth circumstances caused by salinity, the ground surface is constantly moist and lacks vegetation. Lands become very prone to erosion as a consequence. The amount of salt on the soil's surface rises as a result of excessive irrigation owing to evaporation.
Saline soils cause crops to suffer because of high salinity stress, nutritional problems and toxins, poor soil physical conditions, and decreased agricultural output.
Therefore, option B is appropriate.
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please answer this?
Answer:
I think the answer is no. 1
Explanation:
No specific explanation
A cup sits on a table. Due to its position, the potential energy of the cup is 3.00 joules. Ignoring frictional effects, if the cup falls off the table, how much kinetic energy will it have when it is halfway to the floor? a) 3.00 J b) 1.50 J c) 0.00 J d) cannot be determined without knowing the mass and the height of the cups
Answer: 1.50 J
Explanation:
Answer:
1.5 joules
Explanation:
Due to conservation of energy, half way the potential energy will be 1.5J so the remaining 1.5J is kinetic energy.
The periodic table _____. is arranged by atomic mass is arranged by number of protons was developed by early alchemists is divided into vertical periods and horizontal groups
Is the range by number of protons sorry if I'm wrong
Answer:
Is the range by number of protons sorry if I'm wrong
Explanation:
what is chemical safety?
What type of compounds are found in living things; always have carbon within them? (need answer quick)
Answer:
helping hand
Explanation:
dddeedehhhwuww
How many carbon Atoms does NaCI2 have
Answer:
Molecular formula is CaCl2 i.e. 1 atom of Ca and 2 atoms of Cl . Hence, molecular weight = 1 x 40 + 2 x 35.5 = 40 + 71 = 111 g / mol . But if you look at the weight online, it says 110.98 g / mol , which is close to 111
Explanation:
Hope this helped :)
cyclohexene from aminobenzene conversion
Answer:
By dehydrogenation of cyclohexane you may get Benzene as a product. We may use noble metals(Au, Ag, Pt etc.) to dehydration of cyclohexane. Consider following reaction which gives an idea about reaction.
Explanation:
I think it is the correct answer
i have read this in one of the book
how would you know if this combination is likely to be found in some dirt?
Answer:
very unlikely to be found in dirt
Explanation:
That combination has a ratio of ¹⁴N to ¹⁵N of 10:4 = 2.5: 1. The most ¹⁵N enriched natural material has a ratio of ¹⁴N to ¹⁵N on the order of 250 : 1 or higher. The combination shown is very unlikely to be found in dirt.
A student sets up the following equation to convert a measurement. (The ? stands for a number the student is going to calculate.) Fill in the missing part of this equation.
Answer:
1 cm/s
Explanation:
From the question given above,
the student is trying to convert 0.010 m/s to a number in cm/s.
Thus, we can convert 0.010 m/s to cm/s as illustrated below:
Recall:
1 m/s = 100 cm/s
Therefore,
0.010 m/s = 0.010 m/s × 100 cm/s ÷ 1 m/s
0.010 m/s = 1 cm/s
Therefore, 0.010 m/s is equivalent to 1 cm/s
if I took two electrons (negatively charged particles) and tried to put them near each other, what would happen?
Catalase is an enzyme that speeds up the breakdown of hydrogen peroxide in cells. During this reaction oxygen is given off. A scientist designs an experiment to determine how much oxygen is given off when varying concentrations of catalase are used. Identify the independent variable A the concentration of the catalase B the result of the reaction C Type of proxide D the shape of the container
Answer:
The correct option is A
Explanation:
An independent variable is a variable that is intentionally altered (directly or indirectly) and is not dependent on another variable in the course of an experiment. Unlike the independent variable, the dependent variable depends or is presumed to depend on the altered independent variables.
From the explanation above, it can be deduced that the concentration of the catalase is the independent variable as it was intentionally altered (by using different concentrations) in the course of the experiment. The amount of oxygen given off is the dependent variable here
An atom has 17 protons And a mass number of 35 what is the name of this isotope in isotopic notation
Answer:
dsadsaddsadsadsadsdsdasdsa
Explanation:dsadasdasdasdasda
Life has existed on Earth for about 3.8 billion years despite gradual and sudden environmental changes. How do the scientific factors of sustainability help explain how life has continued to survive and evolve?
Answer:
As we all are aware that life on Earth is existed due to several environmental changes and there are several scientific factors of sustainability that support the survival and evolution of life on Earth.
Scientific factors of sustainability include solar energy, chemical cycle, and biodiversity that supported life on Earth. solar energy helps all organism and especially producers to gain energy and store the energy which further used in chemical cycles of transferring energy to other trophic levels.
Chemical cycle also involves the interaction of biotic and abiotic envrionment with each other that leads to environmental changes as well as organisms adapt themselves accordingly.
Biodiversity maintains the balance in the ecosystem and prevent dominancy of one organism otherwise it can lead to scarcity and organism would not be able to survive. Variation in biodiversity due to random mating in the same species leads to evolution and produces new species of organisms.
Hence, scientific factors of sustainability play major role in survival and evolution of life on the Earth.
A climber trekked to the top of Mount Everest, elevation 29,035 ft. From a starting point of 24976 ft. In a time of 15 hr, 35 min. Determine the average rate of climb in:(a) miles per minute
Answer:
The average rate of climb in miles per minute is 8.2x10⁻⁴ miles/min.
Explanation:
The average rate can be calculated as follows:
[tex] \overline{v} = \frac{y_{f} - y_{0}}{t_{f} - t_{0}} [/tex]
Where:
[tex]y_{0}[/tex]: is the initial height = 24976 ft
[tex]y_{f}[/tex]: is the final height = 29035 ft
[tex]t_{0}[/tex]: is the initial time = 0
[tex]t_{f}[/tex]: is the final time = 15 hr, 35 min = 935 min
Then, the average rate of climb in miles per minute is:
[tex] \overline{v} = \frac{y_{f} - y_{0}}{t_{f} - t_{0}} [/tex]
[tex] \overline{v} = \frac{29035 ft - 24976 ft}{935 min - 0} = 4.34 \frac{ft}{min}*\frac{1 mile}{5280 ft} = 8.2 \cdot 10^{-4} miles/min [/tex]
Therefore, the average rate of climb in miles per minute is 8.2x10⁻⁴ miles/min.
I hope it helps you!
Convert 65 mi/hr to in/min
write the steps used for making tea by using the words: solution, solvent,solute,dissolve,soluble, insoluble, filtrate and residue.
answer
Answer:
Water is solvent and milk, tea powder and sugar is solute.
Explanation:
First take a specific mount of water in teapot which is a solvent and heat it for several minutes. After boiling of water, add 1 to 2 table spoon tea powder in water which is a solute and allow it for boiling. After that add milk and sugar according to your preference and tea is made which is a solution. The milk and sugar dissolve in the water but the tea powder did not dissolve so it can be filtrate with the help of filtration tool and all the residue trap at that tool while the tea is clean from all undissolved particles.