True or false The atomic number of an element is always more than the mass number of that element.
Why Should a magnesium ribbon be cleaned before burning ?
A magnesium ribbon is cleaned to remove the protective layer of basic magnesium carbonate from its surface, so that it may readily combine with the oxygen in air (on heating).
Answer:
Magnesium gets covered with a layer of magnesium oxide when kept in air for a long time. This layer hinders the burning of magnesium. Hence, it is to be cleaned before burning.
A chemical bond formed when two atoms share two pairs of electrons is a ________ bond; it is best described as ________.
Answer:
A chemical bond formed when two atoms share two pairs of electrons is a double bond; it is best described as a covalent bond.
Explanation:
A chemical bond in which two pairs of electrons are shared has to be defined as covalent since ionic bonds don't involve electron sharing. They consist only of electrostatic attraction between ions.
What is the Law of Octaves?
A. The rule used to compose a poem of eight lines
B. Law describing the special properties of elements within eight electrons in the outer shell.
C. Each note has a series of eight sub notes increasing in variation between it and the next notes.
D.When ordered by atomic mass every eight elements has similar properties
i believe the answer would be D. When ordered by atomics mass every eighth element has similar properties.
explain with example the need of standard measurement system
Answer:
A standard system of measurement is very important because it helps us from making mistakes at the moment of doing calculations and correctly working...
Answer:
A standard measurement system is important because it allows scientists to compare data and communicate with each other about their results. Metric System – is a measurement system based on the number 10.
A typical scuba tank has a volume of 11 liters and can support a diver for one hour. An adult breathes about 3 liters of air with each breath.
How can an 11-liter tank give a diver enough oxygen for one hour?
Answer:
The correct answer is - at high pressure a huge amount of gases can be stored in less volume.
Explanation:
We already know that pressure is inversely proportional to the volume of gas which means if we increase the pressure the volume of gas becomes less.
P = 1/V
So in the scuba divers tank, the oxygen is filled at very high pressure so the high amount of the oxygen can be filled in less volume and which will last for longer than a normal pressure tank can last.
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Answer:
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The reaction of an alkene and water in the presence of an acid catalyst to produce an alcohol is called ________.
Select from below all elements that follow the DUET rule (not the octet rule). (you can select multiple)
a) Li
b) Mg
c) O
d)He
e) H
f) Ne
Which of the following elements is the largest in size?
A) O
B) He
C) K
ODH
Answer:
C) K
Explanation:
K has an electron configuration of 2.8.8.1
Why do strong bonds exist between water molecules?
They have nonpolar structure.
They are held together by hydrogen bonds.
The hydrogen end of a water molecule is weakly negative.
The shared electrons are more attracted to the hydrogen atom.
Answer: they are held together by hydrogen bonds I believe
Explanation:
The strong bonds exist between water molecules.Because they are held together by hydrogen bonds. Option B is correct.
What is a hydrogen bond?Hydrogen bonding is a bond between hydrogen atom, but rather a sort of dipole-dipole attraction between molecules.
The attractive force between a hydrogen atom covalently bound to a very electronegative atom such as an N, O, or F atom and another extremely electronegative atom causes it.
The strong bonds exist between water molecules.Because they are held together by hydrogen bonds. Hence,option B is correct.
Hence,option B is correct.
To learn more about hydrogen bond, refer:
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what are the six chemicals in production of liquid soaps
1. Sodium triphosphate ·
2. Sodium hydroxide ·
3. potassium hydroxide
4. Sodium Lauryl Sulfate · 5.Hydroxyethylcellulose ·
6. Sodium carbonate
Complete the following blanks on the basis of law of conservation of mass.
1) Na + O2 -----> 2NaO
8 g + 65 g ---> ______
2) 2H2 + O2 → 2H2O
24 g + ____ → 62 g
8g + 65g = 73g
24g + 38g = 62g
Answer:
1)Na + O2 = > 2NaO
8 g + 65 g = > 73g
2) 2H2 + O2 → 2H2O
24 g + 38g→ 62 g
how many moles are in 6.4grams of copper
Answer:
exactly 0.10071444308 mols or just 0.1 mols
Explanation:
converting 6.4 g of copper to moles is done by using it's Molar Mass we can find the Molar Mass by lookin at the periodic table or just googling it. In this case, copper's molar mass is 63.546g per Mole. so thats 6.4/63.546 = 0.015736631731344 moles of copper
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Answer:
no pues nadie te pasa la pagina
3. According to the Arrhenius theory, which list of compounds includes only acids?
A) HF, H2CO3, and HNO3
B) LiOH, HNO3, and CH3OH
C) H2PO4, HCO3, and NH4Cl
D) HNO3, H2SO4, and C6H12O6
Answer:
C) H2PO4, HCO3, NH4Cl
Explanation:
Because all of the above compounds on reaction with water liberate H+ ion which is the identification of an acid acc to Arhenius Theory
equator runs east and west all the way around the world,halfway between the south poles called the ______________and north poles called________________.
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Answer:
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The formal charge and P-O bond order in PO43- respectively are 0.6, -0.75 -0.75, 1.25 1.0, -0.75 1.25, -3 98.
Answer:
-0.75 , 1.25
Explanation:
Number of electrons present in valence shell,
P-O = 5 + 8 = 13
Number of electrons involved in bond formation,
13 - 3 = 10
Number of bonds in PO3 - 4ion = 102
Average P-O bond = 1.25
Average formal charge on Oxygen atom is -0.75
(d) (i) How can the water molecules from the iceberg end up as water in the lake?
Explanation:
If the iceberg is near the lake and the water molecules melt, then the molecules will slide down. The iceberg could be melting for many reasons - it can be purposely destroyed, the sun could be melting it, or it might naturally fall in. So, this is the answer to your question. Hope it helps!
The bottle slides down the hill and is moving at a velocity of 14 meters/second the instant it hits the ground. The vertical height from where Jeff dropped the bottle is meters. Ignore friction, and use , PE = m × g × h, and g = 9.8 m/s2.
Answer:
10 m
Explanation:
From the question given above, the following data were obtained:
Velocity (v) = 14 m/s
Acceleration due to gravity (g) = 9.8 m/s²
Height (h) =?
Next, we shall determine the energy. This can be obtained as follow:
Velocity (v) = 14 m/s
Kinetic Energy (KE) =?
KE = ½mv²
KE = ½ × m × 14²
KE = ½ × m × 196
KE = m × 98
Finally, we shall determine the height. This can be obtained as follow:
Kinetic energy (KE) = m × 98
Acceleration due to gravity (g) = 9.8 m/s²
Height (h) =?
Since the object is falling from a particular height,
Potential energy (PE) = kinetic energy (KE)
PE = mgh
KE = m × 98
m × 9.8 × h = m × 98
Divide both side by m × 9.8
h = m × 98 / m × 9.8
h = 10 m
Thus, the bottle was dropped from a height of 10 m
If an atom has 32 protons in the nucleus, how many electrons will it have orbiting the nucleus
An atom is neutral as it has the same number of electrons that of protons. So, if an atom has 32 protons i.e. the atomic number of it is 32, then it will have 32 electrons revolving the nucleus.
WILL GIVE BRAINLIEST!Which statement best describes electrolytic and voltaic cells?
•Electrolytic cells and voltaic cells each carry out spontaneous reactions.
•Electrolytic cells and voltaic cells each carry out nonspontaneous reactions.
•Electrolytic cells carry out spontaneous reactions, but voltaic cells carry out nonspontaneous reactions.
•Electrolytic cells carry out nonspontaneous reactions, but voltaic cells carry out spontaneous reactions
Answer:
the last answer is right.
Which redox reaction would most likely occur if silver and zinc metal were added to a solution that contained silver and zinc ions?
Answer:
D. Zn²⁺ + 2Ag → Zn + 2Ag⁺
Explanation:
On the reduction potential chart, we have that silver ion Ag⁺ is a stronger oxidizing agent than, zinc, Zn, which is a reducing reducing agent the compared to silver
Therefore, the redox reaction that will occur is that the zinc, Zn, will be oxidized to Zn²⁺ ion, while the silver, Ag²⁺ ion will be reduced to silver deposits Ag, therefore, the zinc will displace the silver in the solution containing silver and zinc ions because zinc is higher than silver in the reactivity series
The reduction potential Zn → Zn²⁺ + 2e⁻ = +0.76
The reduction potential for Ag⁺ + e⁻ → Ag = +0.8
Therefore, given that redox reactions are reversible, we get the following likely redux reaction;
Zn(s) + 2Ag⁺(aq) ⇄ 2Ag(s) + Zn²⁺(aq)
Therefore, from the given options;
Zn²⁺(aq) + 2Ag(s) → Zn(s) + 2Ag⁺(aq) is the reaction most likely to occur.
If hydrofluoric acid is a stronger acid than acetic acid, which statement is most likely true?
The conjugate acid of hydrofluoric acid is weaker than that of acetic acid.
The conjugate acid of hydrofluoric acid is stronger than that of acetic acid.
The conjugate base of hydrofluoric acid is weaker than that of acetic acid.
The conjugate base of hydrofluoric acid is stronger than that of acetic acid.
Answer: The statement conjugate base of hydrofluoric acid is weaker than that of acetic acid is most likely true.
Explanation:
A strong acid upon dissociation gives a weak conjugate base. This can also be said as stronger is the acid, weaker will be its conjugate base or vice-versa.
Hydrofluoric acid is a strong base as it dissociates completely when dissolved in water.
For example, [tex]HF \rightleftharpoons H^{+} + F^{-}[/tex]
The conjugate base is [tex]F^{-}[/tex] which is a weak base.
Acetic acid is a weak acid as it dissociates partially when dissolved in water. So, the conjugate base of acetic acid is a strong base.
[tex]CH_{3}COOH \rightarrow CH_{3}COO^{-} + H^{+}[/tex]
Thus, we can conclude that the statement conjugate base of hydrofluoric acid is weaker than that of acetic acid is most likely true.
If a substance contains ionic bonds, then its properties would include
Answer:
If the substance has high melting/boiling point, if it requires high temperature to dissociate into simpler particles, if it's structure is hard and if it conducts heat and electricity quite frequently, then it would be "Ionic compound" otherwise, it will be covalent compound.Explanation:
If a substance contains ionic bonds, then it’s properties would include high melting and boiling points, a crystalline structure, the ability to dissolve quite easily in water, the ability to conduct electricity, have good insulation and lastly be quite hard and brittle.
If my answer was helpful, would you consider giving me a “Brainliest”?. Thank you :)
Explain specifically how an electron gives off light in an atom.
Answer:
Then, at some point, these higher energy electrons give up their "extra" energy in the form of a photon of light, and fall back down to their original energy level.
Explanation:
When properly stimulated, electrons in these materials move from a lower level of energy up to a higher level of energy and occupy a different orbital.
If you refuse a legal chemical test issued by a law enforcement officer, the Division of Motor Vehicles is required to:
Answer: Revoke the driver's license for at least 12 months
Explanation:
Chemical tests are used in order to measure the amount of drugs or alcohol that is in the body of a person when the person was arrested. To do this, samples of the urine or blood of the person can be taken and the result will be used to know if the person was driving under the influence of alcohol or not.
If the person refuse a legal chemical test issued by a law enforcement officer, the Division of Motor Vehicles is required to revoke the the driver's license of the person for at least 12 months.
How many mm of 0.200 M FeCl3 are needed to react with an excess of K2S to produce 2.75 g of Fe2S3 if the percent yield for the reaction is 65.0%?
Answer:
130 mL
Explanation:
2FeCl3(aq) + 3K2S(aq) -----> Fe2S3(s) + 6KCl(aq)
Percent yield = actual yield/theoretical yield × 100
actual yield = 2.75 g
Theoretical yield = x
65= 2.75/x × 100
x= 2.75 × 100/65
x= 4.2 g
Number of moles of FeCl3 = mass/molar mass = 4.2 g/ 162.2 g/mol = 0.026 moles
Then;
n= CV
n= number of moles
C= concentration
V= volume
V= n/C
V= 0.026 moles/ 0.200 M
V= 0.13 L or 130 mL
Aluminum hydroxide, with heat, creates__
Which of the following
Combination,decomposition,
Single replacement,
Double replacement,
Combustion
Answer: Decomposition is the answer
Explanation: why because aluminium hydroxide would decomposes in the presence of heat and would form an oxide which is aluminium oxide and would also form water as a product.
HOPE THIS HELPS!!
Raw material for rayon comes from
a.cellulose
b.coal
c.petroleum
d.animal bones
Explanation:
the raw material for the rayon come from is cellulose