Answer:
Covalent bond involves the sharing of electrons, while metallic bonds have strong attractions and ionic bonds involve the transferring and accepting of electrons from the valence shell. The adhering property of an atom, in order to arrange themselves in a most stable pattern by filling their outermost electrons orbit
Explanation:
hope it helps:)
Which 2 main body systems work alongside the digestive system?
Which statement best describes the octet rule?
A. When an atom becomes an ion, it gains or loses electrons so that its valence shell holds eight electrons.
B. When an atom becomes an ion, it gains or loses protons so that its nucleus holds eight protons.
C. When an atom becomes an ion, it gains or loses eight electrons.
D. When an atom becomes an ion, it gains or loses eight neutrons.
characteristic line spectra only appear in the visible region of light. true or false
Answer:
The answer is true
Explanation:
bc I took this on edgeunity
The atomic notation for a particular atom of boron is ' B. The
atomic number is while the mass number is
Answer:
5;11
Explanation:
What is cellulose and what does it do?
Answer:
Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to many thousands of β linked D-glucose units. Cellulose is an important structural component of the primary cell wall of green plants, many forms of algae and the oomycetes.
Explanation:
Answer:
Hope this helped.
Explanation:
Cellulose is a molecule, consisting of hundreds – and sometimes even thousands – of carbon, hydrogen and oxygen atoms. Cellulose is the main substance in the walls of plant cells, helping plants to remain stiff and upright. Humans cannot digest cellulose, but it is important in the diet as fibre.
What color is the acetic acid plus methyl orange solution and what does this tell you about where the equilibrium is
Answer:
Red
Explanation:
Acetic acid is an acidic medium. Recall that indicators are organic substances whose color changes in response to change in the pH of the solution. often times, the protonated and deprotonated forms of an indicator have different colors.
However, an equilibrium is set up when an indicator is in acid/ basic medium. Methyl orange is red in acid medium and yellow in basic medium.
Hence while in acetic acid, the equilibrium lies towards the protonated form of acetic acid, hence the solution appears red.
Which is the best molecule to build collegen, muscle repair, and tendon repair?
a
carohydrates
b
lipids
c
nucleic acids
d
Proteins
Answer:
d
Explanation:
collagen is made of proteins
Find ΔHrxn for the following reaction:
2PbS(s)+3O2(g)→2PbO(s)+2SO2(g)
Answer:
ΔH°rxn = -827.5 kJ
Explanation:
Let's consider the following balanced equation.
2 PbS(s) + 3 O₂(g) → 2 PbO(s) + 2 SO₂(g)
We can calculate the standard enthalpy of reaction (ΔH°rxn) from the standard enthalpies of formation (ΔH°f) using the following expression.
ΔH°rxn = [2 mol × ΔH°f(PbO(s)) + 2 mol × ΔH°f(SO₂(g) )] - [2 mol × ΔH°f(PbS(s)) + 3 mol × ΔH°f(O₂(g) )]
ΔH°rxn = [2 mol × ΔH°f(PbO(s)) + 2 mol × ΔH°f(SO₂(g) )] - [2 mol × ΔH°f(PbS(s)) + 3 mol × ΔH°f(O₂(g) )]
ΔH°rxn = [2 mol × (-217.32 kJ/mol) + 2 mol × (-296.83)] - [2 mol × (-100.4) + 3 mol × 0 kJ/mol]
ΔH°rxn = -827.5 kJ
The standard enthalpy of the reaction is -827.5 kJ/mol
The standard enthalpy of reaction [tex]\mathbf{\Delta H^0_{rxn}}[/tex] is the enthalpy change that happens in a system whenever one mole of the matter is converted through a chemical process under normal conditions.
The given reaction can be expressed as:
2PbS(s) + 3O₂(g) → 2PbO(s) + 2SO₂(g)
The standard enthalpy can be represented by the equation:
[tex]\mathbf{\Delta H^0_{rxn} = \sum \Delta _f ^0(products) - \sum \Delta _f^0(reactants)}[/tex]
At standard conditions, the standard enthalpies of formation of the given species are:
ΔH°f(PbO(s)) = 219 kJ/molΔH°f(SO₂(g)) = -296.83 kJ/molΔH°f(PbS(s)) = 100.4 kJ/molΔH°f(O₂(g)) = 0 kJ/mol
∴
[tex]\mathbf{ \Delta H^0_{rxn} = \Big[2 mol \times \Delta H^0_f(PbO(s)) + 2 mol \times \Delta H^0_ f(SO_2(g) )\Big] - \Big[2 mol \times \Delta H^0_f (PbS(s))} + \mathbf{ 3 mol \times \Delta H^0_f(O_2(g) )\Big] }}[/tex]
[tex]\mathbf{\Delta H^0rxn = [2 mol \times (-217.32 kJ/mol) + 2 mol \times (-296.83)] - [2 mol \times (-100.4)} \\ \mathbf{+ 3 mol \times 0 kJ/mol]}}[/tex]
[tex]\mathbf{\Delta H^0rxn = -827.5 \ kJ/mol}}[/tex]
Therefore, we can conclude that the standard enthalpy of the reaction is -827.5 kJ/mol
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Cathode rays are deflected toward a negatively charged plate in an electric field.
True
False
Answer:
true. cathode rays are deflected
What mass of water is produced from the complete combustion of 6.60×10−3 g of methane?
Which of the following is an example of a chemical change that occurs in your home?
A) Water boiling on the stove
B) Composting your own fertilizer
C) Smashing a window with a baseball
D) Adding food coloring to icing for a cake
Help, 8th grade Science
How many moles of H2 are needed to produce 24 moles of NH3?
Answer:
36 mol of H2
Explanation:
The balanced equation of the reaction is given as;
3H2 + N2 --> 2NH3
From the reaction;
It takes 3 mol of H2 reacting with 1 mol of N2 to form 2 mol of NH3
3 mol of H2 = 2 mol of NH3
x mol of H2 = 24 mol of NH3
x = (24 * 3) / 2 = 36 mol of H2
Which of the following best describes the structure of a nucleic acid?
a
Carbon ring(s)
b
Globular or fibrous
c
Single or double helix
d
Hydrocarbon(s)
The escape velocity from Earth’s surface is 1.12*10^4 meters per second. At this speed, how many kilometers would a rocket travel in 3 minutes
Answer:
2016 Km.
Explanation:
The following data were obtained from the question:
Speed (S) = 1.12×10⁴ m/s
Time (t) = 3 mins
Distance (d) =.?
Next, we shall convert 3 mins to seconds. This can be obtained as follow:
1 min = 60 s
Therefore,
3 mins = 3 min × 60 s / 1 min
3 mins = 180 s
Next, we shall determine the distance travelled by the rocket. This is illustrated below:
Speed (S) = 1.12×10⁴ m/s
Time (t) = 180 s
Distance (d) =.?
Speed (S) = distance (d) /time (t)
S = d/t
1.12×10⁴ = d/ 180
Cross multiply
d = 1.12×10⁴ × 180
d = 2016000 m
Finally, we shall convert 2016000 m to Km. This can be obtained as shown below:
1000 m = 1 Km
Therefore,
2016000 m = 2016000 m × 1 Km / 1000 m
2016000 m = 2016 Km
Therefore, the rocket will travel 2016 Km in 3 mins
Carbonic acid, H2CO3, has two acidic hydrogens. A solution containing an unknown concentration of carbonic acid is titrated with potassium hydroxide. It requires 22.9 mL of 1.430 M KOH solution to titrate both acidic protons in 54.2 mL of the carbonic acid solution.
Required:
a. Write a balanced net ionic equation for the neutralization reaction. Include physical states.
b. Calculate the molarity of the carbonic acid solution.
Answer:
a. H₂CO₃(aq) + KOH(aq) ⇄ K₂CO₃(aq) + H₂O(l)
b. 0.603 M
Explanation:
Step 1: Write the neutralization reaction
H₂CO₃(aq) + KOH(aq) ⇄ K₂CO₃(aq) + H₂O(l)
Step 2: Calculate the reacting moles of KOH
22.9 mL of 1.430 M KOH react.
0.0229 L × (1.430 mol/L) = 0.0327 mol
Step 3: Calculate the reacting moles of H₂CO₃
The molar ratio of H₂CO₃ to KOH is 1:1. The reacting moles of H₂CO₃ are 1/1 × 0.0327 mol = 0.0327 mol.
Step 4: Calculate the molarity of H₂CO₃
0.0327 moles of H₂CO₃ are in a volume of 54.2 mL. The molarity of H₂CO₃ is:
M = 0.0327 mol/0.0542 L = 0.603 M
Which of the following statements is true during a solar eclipse?
The moon's light is blocked by the Earth.
The Sun's light is blocked by the Earth.
The Sun's light is blocked from another planet.
The Sun's light is blocked by the Moon.
Answer:
The sun's light is blocked by the moon.
Explanation:
During the eclipse, the moon rotates right in front of the sun, that's why the eclipse is so rare and only happens every four(?) years/
Which pair of elements will form a covalent bond?
Rupert had three substances. A brown substance was a liquid at room
temperature. He hit each of the other two with a hammer. A blue crystal
cracked but did not break. A silver substance flattened but did not crack.
Which two statements could be true?
A. The brown substance is ionic
B. The silver substance is ionic
C. The brown substance is molecular
D. The blue substance is ionic
Answer:
its C and D
C. The brown substance is molecular
D. The blue substance is ionic
Explanation:
did the test !
Two correct statements are B) The silver substance is ionic
C) The brown substance is molecular.
What kind of substance is silver?Silver is a chemical element with the symbol Ag and atomic wide variety 47. categorized as transition steel, Silver is stable at room temperature.
Which substance is molecular?It is a molecular substance, that's a substance with or more atoms, the smallest gadgets of remember joined together via a covalent bond. A covalent bond is a hyperlink created via the sharing of electrons that holds these atoms collectively.
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A plant uses carbon dioxide and water to form food and oxygen. Why is this a chemical change?
Answer:
The plant uses carbon dioxide and water to make an entirely new chemical hence chemical change.
Explanation:
Plants create their own 'food', they turn carbon dioxide water and sunlight to create starch and glucose..
Answer:
The properties of carbon dioxide and oxygen are different.
Explanation:
im taking the exam right now and Im pretty sure it's D The properties of carbon dioxide and oxygen are different.
Which of the following compounds contains polar covalent bonds?
a) CS2
b) LiF
c) F2
d) CH3F
Answer:
no d
Explanation:
it has a permanent dipole
CH₃F compound contains polar covalent bonds in its structure, hence option D is correct.
This happens when the electronegativity of the relevant atoms differs significantly.
The electronegativities of the carbon and fluorine atoms in CH3F are dissimilar. Because fluorine is more electronegative than carbon, it attracts the shared electrons to it, giving the fluorine atom a partial negative charge and the carbon atom a partial positive charge.
A polar covalent bond is created as a result of this unequal charge distribution. CH₃F compound contains polar covalent bonds in its structure.
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Aluminum metal and bromine liquid (red) react violently to make aluminum bromide (white powder). One way to represent this equilibrium is:
Al(s) + 3/2 Br2(l)AlBr3(s)
We could also write this reaction three other ways, listed below. The equilibrium constants for all of the reactions are related. Write the equilibrium constant for each new reaction in terms of K, the equilibrium constant for the reaction above.
1) 2 AlBr3(s) 2 Al(s) + 3 Br2(l)
2) 2 Al(s) + 3 Br2(l) 2 AlBr3(s)
3) AlBr3(s) Al(s) + 3/2 Br2(l)
Answer:
Explanation:
Al(s) + 3/2 Br₂(l) = AlBr₃(s)
K = [ AlBr₃] / [ Al] [ Br₂]³/²
K² = [ AlBr₃]² / [ Al ] ² [ Br₂]³
2 AlBr₃ = 2 Al(s) + 3 Br₂(l) =
K₁ = [ Al ] ² [ Br₂]³ / [ AlBr₃]²
K₁ = ( 1 / K² ) = K⁻²
2 ) 2 Al(s) + 3 Br₂(l) = 2 AlBr₃(s)
K₂ = [ AlBr₃ ]² / [ Al ]² [ Br₂ ]³
K₂ = K²
3 )
AlBr₃(s) = Al(s) + 3/2 Br₂(l)
K₃ = [ Al ] [ Br₂ ] ³/² / [ AlBr₃ ]
= ( 1 / K ) = K⁻¹
Georgia discovered a piece of metal. She measured its mass as 14 grams and its volume as 2 cm3. Georgia then compared the metal she found with the metals in the table below.
DENSITY OF METALS
Which type of metal did Georgia most likely find?
A.Gold
B.Lead
C.Silver
D.Zinc
Answer:
try dividing the grams and the volume and see what number matches up with your answer
Explanation:A certain chemical reaction releases of heat for each gram of reactant consumed. How can you calculate the heat produced by the consumption of of reactant? Set the math up. But don't do any of it. Just leave your answer as a math expression. Also, be sure your answer includes all the correct unit symbols.
Complete Question
The complete question is shown in the first uploaded image
Answer:
So the math expression is
[tex]heat = \frac{ 35. 7 KJ * 1900 \ gram }{ 1 \ gram }[/tex]
Explanation:
From the question we are told that
The heat released for 1 gram of reactant consumed is [tex]H = 37.5 \ KJ/g [/tex]
The mass of reactant considered is [tex]m = 1.9 \ kg = 1900 \ g[/tex]
So if
[tex]37.5 \ KJ [/tex] is produced for 1 gram
Then
x kJ is produced for 1900 g
=> [tex]x = \frac{ 35. 7 KJ * 1900 \ gram }{ 1 \ gram }[/tex]
So the heat released is
[tex]heat = \frac{ 35. 7 KJ * 1900 \ gram }{ 1 \ gram }[/tex]
Which profile best shows the topography alone line AD
Mass number is equal to
(10 Points)
O neutrons and electrons
o electrons and protons
O protons and nucleus
protons and neutrons
SOMEONE PLEASE HELP I WILL GIVE BRAINLIEST PLEASEEEEE!!!!!!!!!!
MY ELEMENT IS NICKEL!!
Answer:
Metallurgy can be isolate other elements. Iron and bronze are the common metalsNickel is the metal which reacts with many metalsSome halogen and discredited metalsHow many liters of H2(g) at STP are produced per gram of Al(s) consumed in the following reaction? 2Al(s)+6HCl(aq)→2AlCl3(aq)+3H2(g)
Answer:
1.24 L of H₂ at STP .
Explanation:
2Al(s) +6HCl(aq) → 2AlCl₃(aq) + 3H₂(g)
2 moles 3 x 22.4 L
2 x 27 g of Al reacts to give 3 x 22.4 L of H₂ at STP .
1 g of Al will react to give 3 x 22.4 / ( 2 x 27 ) L of H₂ at STP .
= 1.24 L of H₂ at STP .
The volume of hydrogen produced by 1 grams of Al has been 1.24 L.
The balanced chemical reaction has been given as:
[tex]\rm 2\;Al\;+\;6\;HCl\;\rightarrow\;2\;AlCl_3\;+\;3\;H_2[/tex]
From the equation, 2 moles of Aluminum gives 3 moles of Hydrogen
The mass of the compound from moles can be given as:
Mass = moles × molecular mass
Mass of 2 moles Al = 2 × 27 g
Mass of 2 moles Al = 54 g
Mass of 3 moles hydrogen = 3 × 2 g
Mass of 3 moles hydrogen = 6 g
From the equation,
54 g aluminum gives = 6 grams hydrogen
[tex]\rm 1\;gram\;aluminum\;=\;\dfrac{6}{54}\;\times\;1[/tex]
1 gram Aluminum = 0.11 grams hydrogen
The mass of hydrogen produced by 1 gram Al has been 0.11g. The moles equivalent to 0.11g hydrogen has been given as:
Mass = moles × molecular mass
0.11 g = moles × 2 g/mol
Mole of hydrogen = 0.055 mol
The moles of hydrogen produced by 1 gram of Al has been 0.055 mol.
According to the ideal gas equation, any gas at STP has 1 mole equivalent to 22.4 L. So,
1 mol = 22.4 L
0.055 mol = 0.055 × 22.4 L
0.055 mol = 1.244 L.
The volume of hydrogen produced by 1 grams of Al has been 1.24 L.
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You have a carbonate buffer with pH 10.3 and a concentration of 2.0 M. What is the buffer capacity of 100 mL of the buffer against 3.0 M CsOH?
Answer:
Explanation:
pH = 10.3
[ H] = 10⁻¹⁰°³
= 5 x 10⁻¹¹ M
concentration of CsOH C = 3 M
pKa of carbonate = 6.35
Ka = 10⁻⁶°³⁵ = 4.46 x 10⁻⁷
Buffer capacity = 2.303 x C x Ka x [ H⁺] / ( Ka + [ H⁺]² )²
= 2.303 x 3 x 4.46 x 10⁻⁷ x 5 x 10⁻¹¹ / ( 4.46 x 10⁻⁷ + 25 x 10⁻²² )²
= 154 x 10⁻¹⁸ / 19.9 x 10⁻¹⁴
= 7.74 x 10⁻⁴ .
Having the same number of valence electrons means having similar chemical properties.
True or False
Answer:
True
Explanation:
Because atoms with the same number of valence electrons react in similar ways with other elements.