Answer:
pretty sure it's false
Explanation:
hope this helps!
_____ are factors that are not tested and remain constant. A. Dependent variables B. Controlled variables C. Independent variables D. Constant variables
Answer:
B. Controlled variables
Explanation:
The Dependent sample t-test compares the mean score of measurements in one group to that of another other group. It mainly used when analyzing comparable sample units as it pairs repeatable observations within a time frame.
Controlled variables are factors that are not tested and remain constant. Some examples of controlled variables are temperature, pressure, volume etc
“Copper pots are the best pots for cooking food quickly.” Which term best describes this statement?
Answer:
because I make eggs and they taste delicious
Answer:
Conclusion
Explanation:
Can someone help me please :)
What is the volume of 0.128 mol of nitrogen dioxide gas at STP?
A) 0.00571 L
B) 2.87 L
C) 5.89 L
D) 132 L
Answer:
B) 2.87 L
Explanation:
A mole of any gas at STP has a volume of about 22.412 liters. So, 0.128 moles of gas will have a volume of ...
0.128 · 22.412 L ≈ 2.87 L
Answer:
B. 2.87 LExplanation:
the volume of 0.138 mol of nitrogen dioxide gas at STP is equal to...2.87 L/litreChemistry, Good amount of points for help!!
Answer:
Where are all my chemistry geniuses at?
1. The pattern of electronegativities would increase as you go across a period and would decrease as you go down a group in the periodic table.
2. There is a correlation between electronegativity and atomic radius. As electronegativity increases, atomic radius decreases. As electronegativity decreases, atomic radius increases. This would make sense because as a atomic radius increases, them more farther away the electrons are away from the nucleus because of their many subshells making it less electronegative. As atomic radius decreases, the electrons are more closer to the nucleus because of their few subshells making the element more electronegative.
3. There is a correlation between ionization energy and electronegativity. As electronegativity increases, ionization energy increases as well. If it decreases, ionization energy decreases too. This makes sense because the more electronegativity the element, the more they are closer to the nucleus(making them harder to remove) and the more desperate for an electron the atom is.
Explanation:
Hope it helped!
After what part of the cell cyle does the cell begin interphase?
A.anaphase
B.prophase
C.cytokinesis
Explanation:
The prefix inter- means between, reflecting that interphase takes place between one mitotic (M) phase and the next. Image of the cell cycle. Interphase is composed of the G1 phase (cell growth), followed by the S phase (DNA synthesis), followed by the G2 phase (cell growth).
Daffodil is ordering office supplies for her company. When she tries to order pencils, she finds that pencils are sold by the gross, which is equal to 144 pencils. Daffodil checks how many pencils her company uses in a year, and decides to order 5 gross of pencils. How many pencils will she receive? Remember to include units (full word, plural, WATCH YOUR SPELLING) as they are worth half of this question.
Answer:
720 pencils
Explanation:
The parameter given are;
The unit quantity by which the pencils are sold = 1 gross
The number of pencils Daffodil orders = 5 gross of pencils
One gross is a quantity equal to twelve dozens
Therefore, we can write;
1 gross = 12 × 12 = 144
From which we have;
5 gross = 5 × 144 = 720
Which gives;
For the 5 gross of pencils Daffodil orders, she receives 720 pencils
The first mass extinction that occurred between the Paleozoic and the Mesozoic Era,
caused the extinction of which organism?
O Wooly mammoth
O Dinosaurs
O Trilobites
Flying Reptiles
Answer:
O Trilobites
Explanation:
The first mass extinction that occurred between the Paleozoic and the Mesozoic era caused the extinction of the trilobites.
Extinction are catastrophic events that causes the loss of organisms on the earth surface. Several factors can lead to extinction.
The first mass extinction took place between the Paleozoic and the Mesozoic era. This wiped out one of the most successful organism on the earth surface at that time. They were the trilobites.Determine the empirical formula for a compound with 68.4% Cr and 31.6% O. Show your work in the space below.
Answer:
Cr2O3
Explanation:
To find the empirical formula, which is the smallest whole number ratio of a compound, the following is done:
68.4% Cr = 68.4g of Chromium
31.6% O = 31.6g of Oxygen
Since, Cr = 52, O = 16, divide each mass by their respective atomic mass to convert to moles.
Cr = 68.4/52 = 1.315 mol
O = 31.6/16 = 1.975 mol
- Next, we divide each mole value by the smallest value (1.315mol)
Cr = 1.315/1.315 = 1
O = 1.975/1.315 = 1.50
The ratio or Cr to O is 1:1.5
We multiply this ratio by 2 to get the whole number ratio as follows:
2 × 1: 2 × 1.5
2:3
Hence, the empirical formula of Cr and oxygen is Cr2O3.
chemistry question help please
Answer:
xii. B. Smelting
xiii. D. Carbon
Explanation:
Smelting is known to be a process by which a metal is gotten. It is gotten either as the element or as a simple compound. This is obtained from metal's ore by heating. The heating can be done ordinarily in the presence of oxidizing agents, like air, or reducing agents, carbon e.g coke.
Zinc is gotten after Zinc oxide is heated in the presence of carbon.
This process is smelting.
Concentrated tetraoxosulphate acid is a strong dehydrating agent. It has the ability to char wood, paper, or sugar, leaving a carbonaceous residue. The charring effect is as a result of the carbon that is found in the wood.
The acid sucks in the oxygen and hydrogen, leaving behind the carbon; this results in the charring effect.
What is the energy of a photon with a frequency of 5.90 × 10¹⁴ s⁻¹? (h = 6.626 × 10⁻³⁴ J • s)
a chemical reaction produces 3.81g potassium chloride (KCl). How many formula units of potassium chloride are there? *Find Molar Mass of KCl*
Answer is 3.08 E 22 formula units, but I need the work shown
Answer:
The number of formula units in 3.81 g of potassium chloride (KCl) is approximately 3.08 × 10²²
Explanation:
The given parameters is as follows;
The mass of potassium chloride produced in the chemical reaction (KCl) = 3.81 g
The required information = The number of formula units of potassium chloride (KCl)
The Molar Mass of KCl = 74.5513 g/mol
[tex]The \ number \ of \ moles \ of \ a \ substance, n = \dfrac{The \ mass \ of \ the substance}{The \ Molar \ Mass \ of \ the \ substance}[/tex]
Therefore, we have;
[tex]The \ number \ of \ moles \ of \ KCl= \dfrac{3.81 \ g}{74.5513 \ g/mol} \approx 0.051106 \ moles[/tex]
1 mole of a substance, contains Avogadro's number (6.022 × 10²³) of formula units
Therefore;
0.051106 moles of KCl contains 0.051106 × 6.022 × 10²³ ≈ 3.077588 × 10²² formula units
From which we have, the number of formula units in 3.81 g of potassium chloride (KCl) ≈ 3.08 × 10²² formula units.
The number of formula units in 3.81 g of potassium chloride (KCl) is approximately 3.08 × 10²²
Given:
Mass of KCl= 3.81 g
To find:
Formula units of KCl=?
Molar Mass of KCl = 74.55 g/mol
So, substituting the values in order to calculate number of moles
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}} \\\\\text{Number of moles}=\frac{3.81}{74.55} \\\\\text{Number of moles}=0.051 \text{ moles}[/tex]
1 mole of a substance = Avogadro's number (6.022 × 10²³) of formula units
Thus, 0.051 moles of KCl will contain
[tex]0.051106 * 6.022 * 10^{23} =3.077588 * 10^{22} \text{ formula units}[/tex]
→The number of formula units in 3.81 g of potassium chloride (KCl)
= 3.08 × 10²² formula units.
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What is a sign that a person may be abusing drugs?
A a change in mood and behavior
B avoiding friends and family members
C a drop in grades and a loss of interest in activities
D all of the above
Answer:
answer is a because drugs do so to the person.
Which pair of compounds has the same empirical formula? C₂H₂ and C₆H₆ C₂H₆ and C₃H₆ C₂H₅OH and CH₃OH CH₃CHO and C₃COOH
Pair of compounds have the same empirical formula :C₂H₂ and C₆H₆
Further explanationGiven
Carbon compound
Required
The same empirical formula
Solution
The empirical formula is the smallest comparison of atoms of compound forming elements.
A molecular formula is a formula that shows the number of atomic elements that make up a compound.
(empirical formula) n = molecular formula
C₂H₂ and C₆H₆
Empirical formula CH
(CH)₂=C₂H₂
(CH)₆=C₆H₆
C₂H₆ and C₃H₈
C₂H₆: Empirical formula CH₃
C₃H₈: Empirical formula C₃H₈
C₂H₅OH and CH₃OH ⇒ Empirical formula
CH₃CHO: Empirical formula : CH₃CHO
CH₃COOH: Empirical formula CH₂O
How many moles are 21.67 L of NH4CI?
Type your answer...
Answer:
0.967mole
Explanation:
Given parameters:
Volume of NH₄Cl = 21.67L
Unknown:
Number of moles = ?
Solution:
We assume that the volume was taken at standard temperature and pressure,
Then;
Number of moles = [tex]\frac{volume }{22.4L}[/tex]
Number of moles = [tex]\frac{21.67}{22.4}[/tex] = 0.967mole
4. When the mole fraction of solute is 1, there is
(a) a 1:1 ratio of solute to solvent.
(b) no solute present.
(c) only solute present.
(d) only solvent present.
(e) 1 mole of solute and 99 moles of solvent.
Answer:
(c) only solute present
Explanation:
In chemistry, the mole fraction, denoted by X, refers to the number of moles of a substance in a compound/mixture divided by the total number of substances in the same compound or mixture.
In this case, we can say that mole fraction represents the number of solutes to the number of solutes and solvent in the solution i.e. X = nA/nA + nB
Where; nA = number of solutes
nB = number of solvent
X = mole fraction.
Based on this analogy, When the mole fraction of solute is 1, there is only solute present. That is; X = 1 / 1 + 0
X = 1/1 = 1.
How many formula units are in 2.58 moles of Caci.?
Answer:
1.55 x 10²⁴ formula units
Explanation:
Given parameters:
Number of moles of CaCl₂ = 2.58moles
Unknown:
Formula units in the compound = ?
Solution:
To solve this problem, we must understand that;
1 mole of a substance contains 6.02 x 10²³ formula units
2.58 moles will contain 2.58 x 6.02 x 10²³ formula units
= 1.55 x 10²⁴ formula units
Hydrogen bonds are in the family of Van der Waals forces. They are weaker than ionic and covalent bonds but they cause interesting changes with different chemicals.
What is one of the changes that hydrogen bonds are responsible for?
A. Cause DNA has the double helix shape.
B. Causes salts quickly dissolve in water.
C. Cause sugar looks like a crystal.
D. Cause liquid H2O to have a larger volume than frozen (solid) H2O
Answer:
The answer is B. Van der Waals forces are weaker than ionic and covalent bonds.
Explanation:
In general, if we arrange these molecular forces from the strongest to weakest, it would be like this:
Covalent bonds > Ionic bonds > Hydrogen bonds > Dipole-Dipole Interactions > Van der Waals forces
Covalent bonds are known to have the strongest and most stable bonds since they go deep and into the inter-molecular state. A diamond is an example of a compound with this characteristic bond.
Ionic bonds are the next strongest molecular bond following covalent bonds. This is due to the protons and electrons causing an electro-static force which results to the strong bonds. An example would be Sodium Chloride (NaCl), which when separated is Na⁺ and Cl⁻.
Van der Waals forces, also known as Dispersion forces, are the weakest type of molecular bonds. They are only formed through residual molecular attractions when molecules pass by each other. It doesn't even last long due to the uneven electron dispersion. It can be made stronger by adding more electrons in the molecule. This kind of molecular bonds appear in non-polar molecules such as carbon dioxide.
HOPE THIS HELPS!!!!!!!!!!!!!!
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The change that Hydrogen Bonds are most likely responsible for would be:
B). Causes salts to quickly dissolve in water.
As per the details provided, the hydrogen bonds are classified into the category of Van der Waals forces and the primary reason behind this has been that it leads salt to solvate immediately in the water. Amongst all the bonds, covalent bonds are characterized as the toughest while ionic bonds and hydrogen bonds are followed by it in terms of strength.The reason for which hydrogen bonds cause the change of allowing salts to dissolve immediately is that it illustrates a weaker strength of molecules due to its formation with residual uneven construction.Thus, option B is the correct answer.
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How many carbon atoms are represented by the model below?
Answer:
3
Explanation:
Please dear lord help me I can’t solve it
If 11 grams of a gas occupies 5.6 liters at STP, what is its gram molecular mass?
The molecular mass of gas = 44 g/mol
Further explanationGiven
5.6 Liters of gas
11 gram of gas
Required
The molecular mass
Solution
STP = Standart Temperature and Pressure , 1 atm 273 K
At STP , 1 mol gas = 22.4 L
So mol of 5.6 Liters gas :
= 5.6 : 22.4
= 0.25 moles
The molecular mass of gas :
= mass : mol
= 11 g : 0.25 moles
= 44 g/mol
sound travel through water at a speed of 1500 m/s. if the frequency of a sound is 1000 Hz, what is the wavelength?
Answer:
λ = 1.5 m
Explanation:
Given data:
Speed of wave = 1500 m/s
Frequency of sound = 1000 Hz
Wavelength of sound = ?
Solution:
Speed of wave = frequency × wavelength
by putting values,
1500 m/s = 1000 Hz × λ
λ = 1500 m/s / 1000 s⁻¹ (Hz = s⁻¹ )
λ = 1.5 m
Answer: 1.5
Explanation:
Well first you do
1500/ 1000= 1.5 which mean
The wavelength is 1.5
A compound XO exists in nature. A scientist wanted to prepare the same compound in his lab based on the law of constant proportion but the formula of the compound that he prepared was found to be XO2. Which postulates of the law of constant proportion did he violate?
Answer:
The postulate that all pure samples of a particular chemical compound contain the same elements combined in the same proportion by mass.
Explanation:
The law of constant composition (or definite proportion) states that all pure samples of a particular chemical compound contain the same elements combined in the same proportion by mass.
This law implies that irrespective of the source of the sample of the compound or the method by which the sample was prepared, as long as the sample is pure, the elements present in the compound are always combined in a specific ratio by mass. For example, water has the molecular formula H₂O. Irrespective of the water source, for example, tap-water, lake, stream, river or rainfall, each pure sample of water will have the constant composition of 2 atoms of hydrogen to one atom of oxygen.
The given compound exists as XO in nature. Therefore, irrespective of the source or method of preparation, every sample of this compound should have the formula XO. Since the compound prepared by the scientist was XO₂, therefore, the postulate that all pure samples of a particular chemical compound contain the same elements combined in the same proportion by mass was violated by the scientist. The scientist must have prepared a different compound of the elemental compositions.
How many seconds in 4.3 years?
In the given question, 136293840 seconds are present in 4.3 years.
A second is a unit of time that is equal to 1/60th of a minute and is used to measure short periods of time.
To convert 4.3 years to seconds, we can use the following conversion factors:
1 year = 365.25 days (accounting for leap years)
1 day = 24 hours
1 hour = 60 minutes
1 minute = 60 seconds
So, we can start by multiplying the number of years by the number of days per year:
4.3 years [tex]\times[/tex] 365.25 days/year = 1577.475 days
Next, we can multiply the number of days by the number of hours per day:
1577.475 days [tex]\times[/tex] 24 hours/day = 37859.4 hours
Then, we can multiply the number of hours by the number of minutes per hour:
37859.4 hours [tex]\times[/tex] 60 minutes/hour = 2271564 minutes
Finally, we can multiply the number of minutes by the number of seconds per minute to get the total number of seconds:
2271564 minutes [tex]\times[/tex] 60 seconds/minute = 136293840 seconds
Therefore, in 4.3 years there are approximately 136293840 seconds.
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What do the red arrows represent
Answer:
There are three forces acting on the skateboard. One of these forces is the weight of the rider. Another is the force of gravity on the board itself. The third is the force of the ground pushing up on the skateboard.
What happens when the compound Mgo is formed? (5 points)
Oxygen transfers two electrons to magnesium.
Oxygen receives two electrons from magnesium.
Magnesium forms an ion with -1 charge; oxygen forms an ion with +1 charge.
Magnesium forms an ion with +1 charge; oxygen forms an ion with -1 charge.
Answer:
Oxygen receives two electrons from magnesium.
Explanation:
Hello!
In this case, considering the chemical reaction by which magnesium oxide is produced:
[tex]2Mg+O_2\rightarrow 2MgO[/tex]
In that case, if we show up the oxidation states, we have:
[tex]2Mg^0+O_2\rightarrow 2Mg^{2+}O^{2-}[/tex]
In such a way, since metals, like magnesium, have the capacity to lose electrons, rather than receive them, we infer why it turns out with +2 rather than -2; thus, we the correct answer is "oxygen receives two electrons from magnesium." because it results with -2 in MgO.
Best regards!
Answer:
Oxygen receives two electrons from magnesium.
Explanation:
Complete the graphic organizer.
Basic Parts of an Atom
Answer:
I'm not sure but I think the answer is electrons, protons and neutrons.
Give the symbol for the element with the following orbital diagram:
↑↓
1s
0000
↑↓
2s
0000
↑↓
↑↓
2p
↑↓
0000
↑↓
3s
0000
↑↓
↑↓
3p
↑↓
0000
↑↓
4s
0000
↑↓
↑↓
↑↓
3d
↑↓
↑
The given orbital diagram are iron and symbol for the element is Fe
Orbital diagrams are a pictorial description of electrons in an atom and where electron go in atom then we have to follow three rules, and the first one being the Auf bau Principle, the Auf bau Principle states that each electron occupies the lowest energy orbital first filled and the second is pauli exclusion principle in which only two electron are present which is in opposite spin and third is hunds rule of maximum multiplicity in which pairing of electron is not possible until orbital are singly occupied this rules are used for filling the electron here given orbital diagram in which 1s²2s²2p⁶3s²3p⁶4s²3d⁶ means the element is iron and symbol of this element is Fe
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Can compounds be broken down into the elements they are made of?
Answer:
yes, some can
Explanation:
because like salt an other compounds by being decomposed
A 1,600-milliliter bucket of paint is at a temperature of 70°F. Then the paint is divided equally into four smaller buckets. Each bucket is at 70°F before the paint is poured.
the temperature of each 400 milliliter bucket is about _____ the temperature of the original bucket of paint.
a.the same as
b.four times
c.one fourth
science
Answer:
a.the same as
Explanation:
The temperature of each 400mL bucket is about the same as the temperature of the original bucket of paint.
This is because the temperature of the paint inside the bucket is not dependent on the amount of paint present.
In this regard, the temperature is an intensive property. So each of the boxes will have a temperature that is the same as that of the original bucket. Each of the particles have the same amount of kinetic energy.