Answer:
the people injected with the drug are the variable group while the people injected with the harmless solution are the control group
Katie looks out her bedroom window on a clear night. The stars in the sky look like tiny points of light.
Katie knows that the Sun is also a star, but it looks much larger than all of the other stars in the sky.
Why do the stars in the night sky look so much smaller than the Sun?
Answer:
The Sun looks bigger than other stars because its more closer to the earth than the stars.the farther anything is distant from us the tinier it will look
Explanation:
plz mark brainliest if thats ok|?
Write the chemical formula for the ionic compound formed by lithium and fluorine.
Answer:
→ LiF
Explanation:
[tex]{ \rm{2Li _{(s)} + F _{2(g)} \dashrightarrow \: 2LiF _{(s)} }}[/tex]
Answer:
[tex]Lithium⟼Li+Fluorine⟼F=LiF[/tex]
Explain the following: Unless the loss of reactant is extreme, only the loss of limiting reactant mass truly introduces error into your theoretical yield calculation.
6. Which of the following statements is/are TRUE of metals and non-metals?
l. Non-metals are heat conductors.
ll.Aluminum, copper and iron are non-metals.
III. Phosphorus and sulfur are poor conductors of heat and electricity
IV. Metals have luster.
A. I only
B. III only
C. III and IV
D. I and II
Answer:
I= true
III=false
iv=true
What are the sources of petrochemicals
Answer:
Petrochemicals are chemical products derived from petroleum, although many of the same chemical compounds are also obtained from other fossil fuels such as coal and natural gas or from renewable sources such as corn, sugar cane, and other types of biomass.
Answer:
The sources of petrochemical are: fossil fuel such as coal and natural gases or from renewable sources such corn, sugar, cane and other types of biomass .
Explanation:
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Answer the image I took, I’m studying for a test, and this specific question is hard
Answer:
specific question is hard for me too
#1. Boyle's Law. A gas with a volume of 4.0 L at a pressure of 205 kPa is allowed to expand to a volume of 12.0 L.
What is the pressure in the container if the temperature remains constant? (Answer is 6.8 kPa).
I NEED TO FIND HOW YOU GET TO THAT ANSWER
The final pressure in the container if the temperature remains constant is 68.3 kPa.
Given the following data;
Initial volume, V1 = 4.0 liters Initial pressure, P1 = 205 kPa Final volume, V2 = 12.0 LitersTo find the final pressure in the container if the temperature remains constant, we would use Boyle's Law:
Mathematically, Boyle's law is given by the formula;
[tex]P_1V_1 = P_2V_2[/tex]
Where;
P1 is the original (initial) pressure. P2 is the final pressure.V1 is the original (initial) volume. V2 is the final volume.Substituting the values into the formula, we have;
[tex]205[/tex] × [tex]4 =[/tex] [tex]12P_2[/tex]
[tex]820 = 12P_2\\\\P_2 = \frac{820}{12}[/tex]
Final pressure, P2 = 68.3 kPa
Therefore, the final pressure in the container if the temperature remains constant is 68.3 kPa.
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Find the sum of the
following:
89.001 + 0.0001 + 348.4 +
49166
Answer: 49,603.4011
Explanation:
Answer:
49603.4011
Explanation:
89.001
+. 0.0001
348.4
49166
answer: 49603.4011
Which of the following atoms would be expected to be diamagnetic in the ground state?
O magnesium (Mg)
O potassiun (K)
O chlorine (CI)
O cobalt (Co)
The atoms that would be expected to be diamagnetic in the ground state is magnesium
The magnetism of an atom refers to its electronic configuration. A diamagnetic atom is an atom whose electrons are all paired.
A paired electron is an electron that occurs in pairs in its orbital shell.
At their respective ground state, the electronic configuration of the given elements are as follows:
The electronic configuration of magnesium is 1s²2s²2p⁶3s². As such its a diamagnetic atom.
The electronic configuration of Potassium is 1s²2s²2p⁶3s²3p⁶4s¹. Hence, Potassium has one unpaired electron in its outermost shell.
The electronic configuration of Chlorine is 1s²2s²2p⁶3s²3p⁵. Hence, Chlorine has one unpaired electron in its outermost shell.
The electronic configuration of Cobalt is 1s²2s²2p⁶3s²3p⁶3d⁷4s². Hence, the unpaired electrons of Cobalt in its outermost shell are three.
Therefore, the atoms that are diamagnetic in the ground state is magnesium.
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A biker rode at 4m/s for 10 seconds. How far did they travel?
A.
0.4 m
B.
2.5 m
C.
14 m
D.
40 m
Answer:
D is the answer, 4 times 10 is 40
What quantity is needed to convert between the moles of a
given sample of a substance and its mass in grams?
a the molar mass of the substance
b the density of the substance
C the physical state of the substance
ht?
d all of the above
Answer:
d
Explanation:
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Which of these correctly describes the layer of Earth that has the highest temperatures?
The crust is the hottest because it is closest to the Sun.
The mantle is the hottest because it is the thickest layer.
The outer core is the hottest because it is composed of liquid rock.
The inner core is the hottest because it is under the most pressure.
Please English
Thank you:)
Answer:
The inner core is the hottest because it is under the most pressure.
Explanation:
brainliest please. . .
Turn on "Show formula". What is the formula of this compound?
Answer:
you can find the answer in this link
https://www.coursehero.com/file/p4kfbhi5/B-Turn-on-Show-formula-What-is-the-formula-of-this-compound-Li2O-C-Turn-on-Show/
Electrons move around the nucleus of atoms in specific shells, shown by the rings around the atoms in the Gizmo. The first ring holds two electrons, and the second holds eight. Observe the sodium and chlorine atoms. How many electrons are there total in each atom?
Answer:
2 electrons is the correct answer hope u pass !!!!!!
what is the number of atoms in 7.25 moles of potassium?
Answer:
4.37*10^24 atoms of K
Explanation:
1 mol=6.022*10^23 atoms (Avogadro's number)
To convert from mols to atoms multiply the mols of K by Avogadro's number.
7.25 mol K * 6.022*10^23 atoms = 4.36595*10^24 atoms
Determine the number of moles in 3.50 x 1023
formula units of BaCl2
Answer:
0.58 molesExplanation:
To find the number of moles in a substance given it's number of entities we use the formula
[tex]n = \frac{N}{L} \\[/tex]
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
[tex]n = \frac{3.5 \times {10}^{23} }{6.02 \times {10}^{23} } = \frac{3.5}{6.02} \\ = 0.581395[/tex]
We have the final answer as
0.58 molesHope this helps you
Zn + O2= ZnO
How many moles of zinc are needed to make 500. g of zinc oxide?
Answer:
5.15 moles
Explanation:
2zn + o2 = 2zno
5.15 2.57 5.15 moles
nzno=500/(16x2+65)= 5.15 moles
-> nzn = 5.15 x 2 ÷ 2 = 5.15 moles
What trophic level has heterotrophs?
a only the second level
b all levels except the first
C only the first level
d only the last level
What is the goal of the metric system
Answer:
One goal of the metric system is to have a single unit for any physical quantity; a second important goal is to minimize the use of conversion factors when making calculations with physical quantities.
Explanation:
Hope this helps.
Which best describes the type of Bond shown?
A. It is an ionic bond because electrons are being shared
B. It is a covalent bond because electrons are being shared
C. It is an ionic bond because electrons are being transferred
D. It is a covalent bond because electrons are being transferred.
please answer this no links please!!
Based on the nature of the types of chemical bonding, the example illustrates covalent bonding because electrons are shared between the carbon and hydrogen atoms.
Chemical bondingChemical bonding or combination occurs when atoms of elements combine to form products.
Chemical bonding can either be;
ionic bonding orcovalent bondingCovalent bondingCovalent bonding involves a sharing of electrons by the atoms of elements involved.
Since the example shows electrons being shared between carbon and hydrogen atoms, the example illustrates a covalent bonding because electrons are shared between the atoms.
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Look at diagram 1 above. What type of eclipse is shown based on the alignment of the Earth, Sun, and Moon?
Solar eclipse
Lunar eclipse
Question 1 of 5
A specific nitrogen atom has 7 protons and 6 neutrons. If this is a neutral
atom, how many electrons does the atom have?
A. 7
B. 13
C. 14
D. 6
SUBMI
Answer:
A.7
Explanation:
because proton equals to electron in neutral
What is the law of conservation of energy and how do we know this is true?
Answer:The law of conservation of energy states that energy can neither be created nor destroyed - only converted from one form of energy to another. This means that a system always has the same amount of energy, unless it's added from the outside. ... The only way to use energy is to transform energy from one form to another.
Answer:
law of conservation of energy is energy cannot be created or destroyed but can be transformed from one form to another
it is true as potential energy can be converted into kinetic energy
calculate the boiling point elevation for solution of 25.0 grams of menthol in 130 grams of ethanol. Ethanol boiling point elevation constant is 1.22 oC/m
Answer:
Explanation:
When a solute is added to a solvent, the vapor pressure of the solvent (above the resulting solution) is less than the vapor pressure above the pure solvent. The boiling point of a solution, then, will be greater than the boiling point of the pure solvent because the solution (which has a lower vapor pressure) will need to be heated to a higher temperature in order for the vapor pressure to become equal to the external pressure (i.e., the boiling point).
The boiling point of the solvent above a solution changes as the concentration of the solute in the solution changes (but it does not depend on the identity of either the solvent or the solute(s) particles (kind, size or charge) in the solution).
I cant give you the answer but I hope this helps.
How many kilograms of nitrogen are present in a 3.50 L sample of N2O
There are 2.72 kilograms of nitrogen present in a 3.50 L sample of N₂O.
To find the mass of nitrogen in N₂O, we must calculate the number of moles of N₂O.
[tex] n_{N_{2}O} = \frac{m_{N_{2}O}}{M{N_{2}O}} [/tex] (1)
Where:
[tex] m_{N_{2}O}[/tex]: is the mass of N₂O
[tex]M_{N_{2}O}[/tex]: is the molar mass of N₂O = 44.013 g/mol
The mass of N₂O can be founded from the density:
[tex] d = \frac{m}{V} [/tex] (2)
Where:
d: is the density of N₂O = 1.22 g/mL
V: is the volume = 3.50 L = 3500 mL
Then, the mass of N₂O is (eq 2):
[tex] m = d*V = 1.22 g/mL*3500 mL = 4270 g [/tex]
Now, the number of moles of N₂O is (eq 1):
[tex] n_{N_{2}O} = \frac{4270 g}{44.013 g/mol} = 97.02 \:moles [/tex]
Knowing that in 1 mol of N₂O we have 2 moles of N, the number of moles of nitrogen is:
[tex] n_{N} = \frac{2\: moles \: N}{1 \:mol \: N_{2}O}*n_{N_{2}O} = \frac{2\: moles \: N}{1 \:mol \: N_{2}O}*97.02 \:moles \:N_{2}O = 194.04 \: moles [/tex]
Finally, with the number of moles of N we can find its mass:
[tex] m = n_{N}*M_{N} = 194.04 \:moles*14.007 g/mol = 2717.9 g = 2.72 kg [/tex]
Therefore, there are 2.72 kilograms of nitrogen.
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The variable that we change or test in an experiment is called the
A) Dependent variable
B) Independent variable
C) Constant
the variable that we change in an experiment is the Independent Variable. The dependent variable is the outcome and the constant is what remains the same throughout the experiment.
37. A patient had pale tinger nail, shortness of breath and felt dizzy. The patient is most likely suffering from A. Kwashiorkor B. Marasmus C. Anaemia D. Rickets
Answer:
Anaemia
Explanation:
Symptoms: fatigue, skin pallor, shortness of breath, lightheadedness, dizziness, or a fast heartbeat.
When floating a ping-pong ball with a hairdryer, which two forces are balanced?
Answer:
The ping-pong ball will fly up with the air from the hair dryer until it reaches a point of balance – this is where the force of gravity (which pushes the ping-pong ball down) is equal to the force of the air (which is pushing the ping-pong ball up) hop it helps:)
freezing point depression is
A solution made from pure Potassium hydroxide contained 1.85 g of Potassium hydroxide in exactly 200 cm3 of water. Using phenolphthalein indicator, titration of 20.0 cm3 of this solution is carried out v/s sulphuric acid. 9.35 cm3 of sulphuric acid solution is required for complete neutralisation. [atomic masses: K= 39, O = 16, H = 1]
(a) write the equation for the titration reaction.
(b) calculate the molarity of the Potassium hydroxide solution. (c) calculate the moles of Potassium hydroxide neutralised. (d) calculate the moles of sulphuric acid neutralised.
(e) calculate the molarity of the sulphuric acid.
The concentration of H2SO4 is 0.176 M. The number of moles of H2SO4 is 0.0165 moles.
The equation of the reaction is;
2KOH(aq) + H2SO4(aq) ------> K2SO4(aq) + H2O(l)
The number of moles of KOH = 1.85 g/56 g/mol = 0.033 moles
concentration = number of moles /volume
volume = 200 cm3 or 0.2 L
concentration of KOH = 0.033 moles/0.2 L = 0.165 M
From the titration formula;
CAVA/CBVB =na/nb
CA = concentration of acid
VA = volume of acid
CB = concentration of base
VB = volume of base
na = number of moles of acid
nb = number of moles of base
Making CA the subject of formula;
CA = CBVBna/VAnb
CA = ?
CB = 0.165 M
VA = 9.35 cm3
VB = 20.0 cm3
na = 1
nb =2
CA = CBVBna/VAnb
CA = 0.165 M × 20.0 cm3 × 1/9.35 cm3 × 2
CA = 0.176 M
The concentration of sulphuric acid is 0.176 M
From the reaction equation;
2 moles of KOH reacts with 1 mole of H2SO4
0.033 moles of KOH reacts with 0.033 moles × 1 mole/2 moles
= 0.0165 moles of H2SO4
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