Which of the following atoms is expected to have two unpaired electrons?
Al
Mg
Na
None of the above
Answer:
none of the above answers
Describe the differences between models and scientific laws and theories. (
Answer:
Scientific laws and theories have different jobs to do. A scientific law predicts the results of certain initial conditions. ... In simplest terms, a law predicts what happens while a theory proposes why. A theory will never grow up into a law, though the development of one often triggers progress on
Explanation:
what happens when we mix stone in water observation
Answer:
hope it's help you dear
Explanation:
If one drops a stone into a pond, a very rapid, thin jet of water spouts upwards. ... A cavity forms behind the object during impact on the water surface. This cavity is subsequently compressed by hydrostatic pressure, which leads to the formation of the jet
The reaction described by the equation X + Y Z
shown to have the following rate law:
R = K[X] [Y]
What is the effect on the rate if the concentration
of [X] is doubled and [Y] remains constant?
Assuming equimolar quantities of reactants, which compound will react to the greatest extent with boron trifluoride (BF3) in a Lewis acid-base reaction
To solve such this we must know the concept of acid-base reaction. Therefore, NH[tex]_3[/tex] is the compound that will react to the greatest extent with boron trifluoride (BF[tex]_3[/tex]) in a Lewis acid-base reaction.
What is chemical reaction?Chemical reaction is a process in which two or more than two molecules collide in right orientation and energy to form a new chemical compound. The mass of the overall reaction should be conserved. There are so many types of chemical reaction reaction like combination reaction, double displacement reaction.
NH[tex]_3[/tex] is an example of a Lewis Base that will react extensively with BF[tex]_3[/tex] to form the compound NH[tex]_3[/tex] + BF[tex]_3[/tex] → [B (NH[tex]_3[/tex])F[tex]_3[/tex]].
Therefore, NH[tex]_3[/tex] is the compound that will react to the greatest extent with boron trifluoride (BF[tex]_3[/tex]) in a Lewis acid-base reaction.
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calculate mass of MnO2 if 1 mole of KMnO4 completely burnt. 2KMnO4 -> K2MnO4+MnO2+O2
Answer: 80 grams
Explanation:
2KMnO4 -> K2MnO4+MnO2+O2
2 moles of KMnO4 would produce 1 mole of MnO2, so 1 mole of KMnO4 would produce 0.5 moles of MnO4. The molar mass of MnO4 is 160 g/mole. 1/2 mole of KMnO4 would therefore be (160 g/mole)*(0.5 moles) = 80 grams.
The mass of an atom of element x is equivalent to the total mass of 7 hydrogen atoms
How can the Swartz process be modified to work for bacteria? Explain.
Answer:
https://swartzbiotechnologylab.sites.stanford.edu/research
Explanation:
Alkyl chlorides and alkyl bromides are typically transformed into alkyl fluorides in the organic reaction known as the Swarts Reaction.
Swartz reaction?Frederick Jean Edmond Swarts first reported this procedure in 1892. Heating the alkyl chloride or alkyl bromide in the presence of heavy metal fluorides like AGF, Hg2F2, CoF2, or SbF3 causes this reaction.
Swartz process can be used to modify work for bacteria. Bacterial biofilms are collections of microorganisms where the cells are immersed in an extracellular polymeric matrix that the bacteria have self-produced.
In contrast to planktonic bacteria, which are in a state of free movement in a bulk solution, this situation is very different.
Applications:
In this process, alkyl fluorides are created.Fluorinated aliphatic organic molecules, or Freons, are produced via a different variation of the same process.Anhydrous hydrogen fluoride is fluorinated to produce Freons in the presence of antimony salts, which exhibit the oxidation states +3 and +5.Therefore, Alkyl chlorides and alkyl bromides are typically transformed into alkyl fluorides in the organic reaction known as the Swarts Reaction.
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6. Heat from the sun reaches to us by
(a) radiation
(b) conduction
(c) convection
(d) all of these
PS. the one who gets it correct will be followed by me and also be marked as the brainliest!
Answer:
radiation
....
.
.
.
.hi how r u
Is my answer correct
Answer:
Radiation
Explanation:
Heat from the sun reaches is by the process of radiation
Which of these outcomes is conclusive evidence that mixing sugar in water is a physical change?
Answer:
» Water changes from colorless to a pale colored solution.
» The solubility of water reduces because a saturated solution is formed.
» The freezing point of water decreases. [colligative property]
» The boiling point of water elevates [colligative property]
» The vapour pressure of water lowers [colligative property]
Explanation:
[tex].[/tex]
When a liquid is at its boiling point, the vapor pressure of the liquid
9. Hydrogen is 99% H, 0.8% ?H, and 0.2% H. Calculate its average atomic mass.
Answer: Technically, this cannot be answered, since none of the H atoms have a mass number assigned. With the assumption noted delow, I calculate 1.012 as the average atomic mass.
Explanation:
My answer is based on assumed masses for the three H isotopes:
1H : 1 AMU
2H: 2 AMU Deuterium
3H: 3AMU Tritium
AMU Rel Abund. Wt. Avg
1H 1 99.00% 0.99
2H 2 0.80% 0.016
3H 3 0.20% 0.006
Sum 1.012
Is thallium, TI, a solid, liquid, or gas?
Answer:
Thallium is a Solid
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what is the density of a 5 mL sample of 1.95g of Gold
Answer:
density=mass/volume
=1.95/5 = 0.39 g(mL)-¹
why hydrogen has dual nature?
Answer:
Since hydrogen has a single electron in its valence shell, it exhibits dual nature. of the periodic table, or it can obtain one electron to complete its valency of two, such as halogens from Group 17. Since it only has one electron in its outer shell, hydrogen has a dual existence.
Explanation:
This means that, like a normal halogen, a hydrogen atom can easily gain an electron to form a complete outer shell, or lose an electron to form an alkali metal. Since it already has two electrons in its outer shell, hydrogen can be diatomic, rendering it unreactive.
What is 47.35 dL= mL?
Answer:
4.735 litres
Explanation:
10 dL = 1 litre
47.35 dL = 47.35/10 = 4.735 litres
You are unable to lift an object. Which property makes the object difficult to lift?(1 point)
mass
density
weight
volume
Answer:
You are unable to lift an object. Which property makes the object difficult to lift?(1 point)
weight
The specific gravity of a vegetable oil is 0.92. What is the massgrams, of 330 mL of vegetable oil?
Answer:
HOPE THIS ANSWER WILL HELP YOU
In a year an adult cow produces around 3.571 x 10^27 molecules of methane CH4 a greenhouse gas how many moles of methane does this cow produce in a year
Answer:
[tex]\boxed{\boxed {\sf 5930.0 \ mol \ CH_4}}[/tex]
Explanation:
We are asked to find how many moles of methane (CH₄) a cow produces in a year. We must convert molecules of methane to moles of methane. We will do this using Avogadro's Number or 6.022 × 10²³. This is the number of particles (atoms, molecules, formula units, etc.) in 1 mole of a substance.
In this case, the particles are molecules of methane. There are 6.022 × 10²³ molecules of methane in 1 mole.
We will convert molecules to moles using dimensional analysis. Set up a ratio using Avogadro's Number.
[tex]\frac {6.022 \times 10^{23} \ molecules \ CH_4}{ 1 \ mol \ CH_4}[/tex]
We are converting 3.571 × 10²⁷ molecules of methane to moles, so we multiply the ratio by this value.
[tex]3.571 \times 10^ {27} \ molecules \ CH_4 *\frac {6.022 \times 10^{23} \ molecules \ CH_4}{ 1 \ mol \ CH_4}[/tex]
Flip the ratio. It is still the same value, but the units of molecules of methane cancel.
[tex]3.571 \times 10^ {27} \ molecules \ CH_4 *\frac { 1 \ mol \ CH_4}{6.022 \times 10^{23} \ molecules \ CH_4}[/tex]
[tex]3.571 \times 10^ {27} *\frac { 1 \ mol \ CH_4}{6.022 \times 10^{23} }[/tex]
[tex]\frac {3.571 \times 10^ {27}}{6.022 \times 10^{23} } \ mol \ CH_4[/tex]
[tex]5929.923613 \ mol \ CH_4[/tex]
The original measurement of molecules of methane( 3.571 × 10²⁷ molecules) has 4 significant figures, so our answer must have the same. For the number we calculated, that is the ones place. The 9 in the tenth place tells us to round the 9 in the ones place up to a 0, then the 2 in the tens place up to a 3.
[tex]5930 \ mol \ CH_4[/tex]
We must add a placeholder zero in the tenth place to reach 4 sig figs.
[tex]5930.0 \ mol \ CH_4[/tex]
The adult cow produces approximately 5930.0 moles of methane in a year.
Which of the following words means "the degree to which a measurement is precise and reliable"?
a. variable
b. accuracy
c. parameter
d. constant
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Answer:
19.278049929737628457607385688801
Explanation:
Volume = L * W * H
Volume = 17.78 * 9.21 * 4.45 = 728.70441
Density = Mass / Volume
Mass = 14,048
14,048 / 728.70441 = 19.278049929737628457607385688801
Density = 19.278049929737628457607385688801
Explanation:
So density = mass/volume
Using this formula we'll solve the question.
mass = 14,048g/1000 = 14.048 kg
volume = 17.78/100 x 9.21/100 x 4.45/100
volume = 0.3143 m³
density = 14.048 kg/ 0.3143 m³
density = 44.69 kg/m³
round off to = 44.7 kg/m³
Which of the following is an example of a change from gravitational potential
energy to kinetic energy?
Answer:
The speed of a roller coaster increases as gravity pulls it downhill and is greatest at its lowest point. Viewed in terms of energy, the roller-coaster-Earth system's gravitational potential energy is converted to kinetic energy
Explanation:
a ball held in the air is the example of a change from gravitational potential energy to kinetic energy.
write any two effect of gravity
List of choices for questions 20-24: A. (1) CH3MgBr, (2) H3O , (3) CH3MgBr, (4) H3O B. (1) LDA, (2) CH3I, (3) H3O C. (1) CH3MgBr, (2) H3O , (3) NaBH4, (4) H3O D. (1) DIBAH, (2) H3O E. (1) NaOH, heat, (2) SOCl2, (3) CH
Answer:
h30
Explanation:
Water is placed into a sealed jar and has a mass of 22.0 grams. The jar is placed in the freezer and the water turns to ice. The jar of ice is measured. The mass should be:
a. Slightly less than 22.0 grams
b. Exactly 22.0 grams
c. Slightly more than 22.0 grams
exactly 22.0 grams
because freezing is a physical change not a chemicl change..so nothing is taken away or added
ANSWER;
exactly 22.0 grams
because freezing is a physical change not a chemicl change..so nothing is taken away or added
b. Use the balanced equation to answer the following questions.
CuSO4(aq) + 2NaOH(aq) —->Cu(OH)2(s) + Na2SO4(aq)
i. What is the ratio of moles of CuSO4 to moles of NaOH?
ii. If 638.44 g CuSO4 reacts with 240.0 NaOH, which is the limiting reagent?
iii. Using the limiting reagent to determine how many grams of Cu(OH)2 should precipitate out in the reaction.
iv. If only 174.6g of Cu(OH)2 precipitate were actually collected from the reaction, what would the percent yield be?
Answer:
i. 1 : 2
ii. NaOH is the limiting reagent
iii. 292.5g
iv. 59.69%
Explanation:
I have the detailed and self-explanatory workings. will snap and post later. Battery percent at 15%, flashlight not working.
1. The ratio of CuSO₄ to NaOH is 1 : 2
2. The limiting reactant is NaOH.
3. The mass of Cu(OH)₂ that will precipitate out is 292.5 g.
4. The percentage yield of Cu(OH)₂ is 59.7%
1. Determination of the ratio of CuSO₄ to NaOH.
CuSO₄ + 2NaOH —> Cu(OH)₂ + Na₂SO₄
From the balanced equation above, we can see that the ratio of CuSO₄ to NaOH is 1 : 2
2. Determination of the limiting reactant.
CuSO₄ + 2NaOH —> Cu(OH)₂ + Na₂SO₄
Molar mass of CuSO₄ = 63.5 + 32 + (16×4) = 159.5 g/mol
Mass of CuSO₄ from the balanced equation = 1 × 159.5 = 159.5 g
Molar mass of NaOH = 23 + 16 + 1 = 40 g/mol
Mass of NaOH from the balanced equation = 2 × 40 = 80 g
From the balanced equation above,
159.5 g of CuSO₄ reacted with 80 g of NaOH.
Therefore,
638.44 g of CuSO₄ will react with = (638.44 × 80) / 159.5 = 320.22 g of NaOH.
From the calculations made above, we can see that a higher mass (i.e 320.22 g) of NaOH than what was given (i.e 240 g) is needed to react completely with 638.44 g of CuSO₄.
Therefore, NaOH is the limiting reactant.
3. Determination of the mass of Cu(OH)₂ that will precipitate out.
CuSO₄ + 2NaOH —> Cu(OH)₂ + Na₂SO₄
Molar mass of Cu(OH)₂ = 63.5 + 2(16 + 1) = 97.5 g/mol
Mass of Cu(OH)₂ from the balanced equation = 1 × 97.5 = 97.5 g
From the balanced equation above,
80 g of NaOH reacted to produce 97.5 g of Cu(OH)₂.
Therefore,
240 g of NaOH will react to produce = (240 × 97.5) / 80 = 292.5 g of Cu(OH)₂
Thus, 292.5 g of Cu(OH)₂ precipitated out of the reaction.
4. Determination of the percentage yield.
Actual yield of Cu(OH)₂ = 174.6 gTheoretical yield of Cu(OH)₂ = 292.5 gPercentage yield of Cu(OH)₂ =?Percentage yield = (Actual /Theoretical) × 100
Percentage yield of Cu(OH)₂ = (174.6 / 292.5) × 100
Percentage yield of Cu(OH)₂ = 59.7%
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Phosphorous-32 has a half life of 14.3 days while radon-222 has a half-life of 3.8 days, so phosphorous-32 is considered more active.
a. True
b. False
What are the differences of a physical change and a chemical change?
Answer:
a physical change only changes the look of something whereas a chemical change occurs when one thing has a reaction and it forms a new substance.
compared to those
5. Electrons farther away from the nucleus in an atom have
closer to the nucleus.
O A. lower energy
OB. higher energy
O C. the same energy
O D. higher or lower energy, depending on the element
Explanation:
higher or lower energy, depending on the element
Answer:
B
Explanation:
h = 3.0 a + 28.2
A pediatrician uses the model above to estimate the height h of a girl, in inches, in terms of the girl's age a, in years. Based on the model, what is the estimated height of a 2-year-old girl?
Answer:
h = 34.2 in
Explanation:
h = 3.0a + 28.2
h = height of a girl.
a = age of a girl.
h = 3.0a + 28.2
h = 3.0(2) + 28.2
h = 6 + 28.2
h = 34.2
The estimated height of a 2-year-old girl is 34.2 in.
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