The average atomic mass unit of Silicon : 28.0774
Further explanationGiven
Isotopes of Si(Silicon-28, Silicon-29, Silicon-30)
Required
The average atomic mass
Solution
Isotopes are elements that have the same Atomic Number (Proton)
Atomic mass is the average atomic mass of all its isotopes
Avg. atomic mass = %mass.isotopes 1 + %mass.isotopes 2...etc
Input the values :
Avg atomic mass = (0.922 x 27.977) + (0.047 x 28.976) + (0.031 x 29.974)
Avg atomic mass = 28.0774
HELPPPPPPPPPPPPPPPPPP
Answer:
*helps and doesnt get deleted*
Explanation:
How many electrons must nitrogen gain to become like it’s closest noble gas, Neon?
Answer:
3
Explanation:
The following is a procedure that was theoretically performed by a student. Read through the procedure and answer the questions below.1.A 10.0 mL graduated cylinder to measure 10.0 mL of a 1.00 M CaCl2 solution into an initially empty 50.0 mL beaker.2.A 50.0 mL graduated cylinder was then used to measure out 25.0 mL of 0.500 M K2CO3. This K2CO3solution was then added to the beaker containing the CaCl2 solution. The solution became cloudy, and the student concluded that a precipitate must have formed. Write a balanced chemical reaction below, including phases, and identify the chemical formula of the precipitate:
Answer:
CaCl2 (aq) + K2CO3(aq) ---------> CaCO3(s) + 2KCl(aq)
Explanation:
We have the reactants as calcium chloride and potassium carbonate. Recall that we are expecting that the reaction will yield a precipitate. We must keep that in mind as we seek to write its balanced chemical reaction equation.
So we now have;
CaCl2 (aq) + K2CO3(aq) ---------> CaCO3(s) + 2KCl(aq)
Recall that the rule of balancing chemical reaction equation states that the number of atoms of each element on the right side of the reaction equation must be the same as the number of atoms of the same element on the left hand side of the reaction equation.
What are the names of the compounds containing silver?
Show the compound formula and their names. (WRITE CLEARLY AND NEATLY OR THE QUESTION WILL BE CONSIDERED WRONG)
Answer:
the silver compounds include:
silver chloride agcl ,
silver bromide agbr ,
and silver iodide agi.
Based on the number of valence electrons indicated by its location in the periodic table ,which elements behavior would you predict to be closest to that of potassium (k)
Answer:
Na sodium or Rb rubidium
Explanation:
Because Na is present in first group all members of group 1 have 1 electron in valence shell and show similar properties.
You have a 500.0 ml graduated cylinder filled with 100.0 mL of water. You carefully add a 178.5 gram piece of iron (density of iron = 7.87 g/mL). What is the final volume reading in the graduated cylinder after adding the iron piece?
Answer:
122.7 mL
Explanation:
Step 1: Given data
Volume of water: 100.0 mLMass of the piece iron (m): 178.5 gDensity of iron (ρ): 7.87 g/mLStep 2: Calculate the volume of the piece of iron
Density is equal to the mass of the piece divided by its volume.
ρ = m/V
V = m/ρ
V = 178.5 g/(7.87 g/mL) = 22.7 mL
Step 3: Calculate the volume of the mixture
The volume of the mixture is equal to the sum of the volume of water and the iron piece.
100.0 mL + 22.7 mL = 122.7 mL
9. What metric unit would be most
appropriate to use when measuring
the length of a paperclip?
a. Millimeter
b. Decimeter
c. Meter
d. Kilometer
Answer: a. Millimeter
Explanation:
A paperclip is a small device or instrument that can be used to hold the papers or stack of papers together. The length of the paperclip can be measured using millimeter. It is equal to the thousands of meters. The millimeter is a dimension which is used to measure the very small length objects which have visible scale distances and length.
Decimeter can be used to measure the length of the object smaller than paperclips. Meter and kilometers are used for objects and distances larger than paperclip.
Which of these can be found in a plant cell, but not in an animal cell?
Answer:
Hey!
Explanation:
I dont know the answers but Cell walls and Cloroplasts are only in plant cells. I hope this helps!
Calculate the temperature change when 2.00 L at 293 K is compressed to 1.00 L.
Answer:
[tex]\Delta T=-146.5K[/tex]
Explanation:
Hello!
In this case, given the Charles' law which allows us to understand the volume-temperature behavior as shown below:
[tex]\frac{T_1}{V_1}=\frac{T_2}{V_2}[/tex]
Thus, given that we need to calculate the final temperature after the compression, we obtain:
[tex]T_2=\frac{V_2T_1}{V_1}=\frac{1.00L*293K}{2.00L}\\\\T_2=146.5K[/tex]
Thus, the temperature change would be:
[tex]\Delta T=T_2-T_1=146.5K-293K\\\\\Delta T=-146.5K[/tex]
Best regards!
Imagine an alternate universe where the value of the Planck constant is 6.6207 x 10^-36 J*s.
In that universe, which of the following objects would require quantum mechanics to describe, that is, would show both particle and wave properties? Which objects would act like everyday objects, and be adequately described by classical mechanics?
1. A buckyball with a mass of 1.2 x 10-21 g, 0.7 nm wide, moving at 38. m/s.
classical or quantum?
Answer:
See explanation
Explanation:
According to Louis de Broglie, matter has an associated wavelength. He was the first scientist to establish the idea of wave-particle duality or wave- particle paradox.
The display of wavelike properties by objects in the universe is dependent on the magnitude of the of the mass of the body. Small objects have a large associated wavelength and can be described completely by quantum mechanics.
A buckyball with a mass of 1.2 x 10-21 g, 0.7 nm wide, moving at 38. m/s has a very small mass and significant associated wavelength hence the system can be completely described by quantum mechanics.
A mixture is made by combining 1.29 lb of salt and 5.35 lb of water.
What is the percentage of salt (by mass) in this mixture?
Answer:
19.47%
Explanation:
[tex]\frac{1.29}{1.29+5.35}[/tex]
Please recheck, for this answer may not be correct
is a planar carbon "backbone" possible for propane? Explain.
Is a planar carbon "backbone" possible for cyclopropane? Explain.
Answer:
Cyclopropane has a planar carbon back bone while propane does not
Explanation:
We have to recognize that in straight chain saturated organic compounds, carbon atoms have a tetrahedral geometry. Each carbon atom is bonded to four other atoms.
However, carbon atoms in cyclic compounds are also sp3 hybridized with each carbon bonded to only four other atoms but the ring system is highly strained.
Cyclopropane is a necessarily planar molecule with a bond angle that is far less than the expected tetrahedral bond angle due to strain in the molecule. Hence, the carbon atoms may have have a "planar backbone".
6. Three of these terms belong together. Which one doesn't belong?
A) nucleus
B) cytoplasm
C) cell wall
D) cell membrane
Explain why the one you chose doesn't belong with the other three?
Answer:
i am 50/50 at the memoent but i have a feeling it is the cytoplasm as it isnt a cell like the others. Hope this helps :(
Explanation:
Mount Everest is 29,029 feet high. What is
the height of Mount Everest in kilometers?
Answer:
8.849 kilometres
Explanation:
this is the height in kilometers
What happens to water when it changes to ice
Answer:The atoms cool down and become slower and their bonds become close and they move less.
Explanation:I took science
Draw a Lewis structure of the molecule that matches the description below. All non- H atoms should have full octets, and all formal charges should be zero. Unless you're told otherwise, assume there are no rings in the molecule.
Description: The molecule is composed of
2 C 's, 5 H 's, and 1 N and it contains a C - C double bond.
Answer:
See attached picture.
Explanation:
Hello!
In this case, according to the given instructions, on the attached picture you will find the required Lewis structure, whereas there is a double bond between the two carbon atoms, and one of those is bonded to the nitrogen; moreover the terminal carbon has two out of five hydrogen atoms, the middle carbon, one out of five and the nitrogen atom has two out of five hydrogen atoms; therefore the molecule would be ethenamine.
Best regards!
Which of the following does NOT determine local weather patterns?
Answer:
do you have a picture of the choices?
A solution was diluted 1/40, and the final concentration was 20%. What was the original concentration?
The original concentration : 800%
Further explanationGiven
Diluted 1/40
Final concentration 20%
Required
The original concentration
Solution
Dilution is the process of adding solvent to get a more dilute solution.
The moles(n) before and after dilution are the same.
Can be formulated :
n₁ = n₂
M₁.V₁ = M₂.V₂
diluted 1/40(dilution factor)⇒ V₁/V₂=1/40⇒V₂/V₁=40
M₂ = 0.2(20%)
Input the value for M₁ :
M₁=M₂ x (V₂/V₁)
M₁ = 0.2 x 40
M₂ = 8(800%)
=
atom ,molecule, proton neutron electron, elements/compounds from SMALLEST to the BIGGEST.
Answer:
Electron,Protons/Neutrons,Atom,Molecule
Explanation:
True or false: potential energy increases as like charges get closer to one another
How many moles of ethane gas, C2H6(g), will occupy 15.0 L at 30 degrees Celsius and 5.0 atm?
Answer:
3 mol
Explanation:
Given data:
Volume of ethane = 15.0 L
Temperature = 30°C
Pressure = 5.0 atm
Number of moles of ethane = ?
Solution:
PV = nRT
P= Pressure
V = volume
n = number of moles
R = general gas constant = 0.0821 atm.L/ mol.K
T = temperature in kelvin
Now we will convert the temperature.
30+273 = 303 K
5.0 atm × 15.0 L = n×0.0821 atm.L/ mol.K × 303 K
75 atm.L = n× 24.87 atm.L/ mol
n = 75 atm.L / 24.87 atm.L/ mol
n = 3 mol
Isopropanol burns in oxygen to yield carbon dioxide, water, and heat. Which word equation best represents this chemical reaction?
isopropanol Right arrow. carbon dioxide + water + heat
isopropanol Right arrow. carbon dioxide + water + oxygen
isopropanol + oxygen Right arrow. carbon dioxide + water + heat
isopropanol + oxygen + heat Right arrow. carbon dioxide + water
Answer:
isopropanol + oxygen Right arrow. carbon dioxide + water + heat
Explanation:
Word equation:
isopropanol + oxygen → carbon dioxide + water + heat
Chemical equation:
2C₃H₇OH + 9O₂ → 6CO₂ + 8H₂O + Heat
The given reaction is combustion of isopropanol. Isopropanol burn in the presence of oxygen and produced carbon dioxide and water. Heat is also produced in this reaction.
The given reaction also follow the law of conservation of mass. There are equal number of moles of each element on both side of reaction equation thus mass remain conserved.
isopropanol + oxygen Right arrow. carbon dioxide + water + heat
The following information should be considered:
Word equation:
isopropanol + oxygen → carbon dioxide + water + heat
Chemical equation:
[tex]2C_3H_7OH + 9O_2 \rightarrow 6CO_2 + 8H_2O + Heat[/tex]
The given reaction is combustion of isopropanol. Isopropanol should be burn with the presence of oxygen and generated carbon dioxide and water. Heat is also generated in this reaction. The given reaction also follows the law of conservation of mass
Learn more; https://brainly.com/question/1691136?referrer=searchResults
How are electricity and magnetism related?
Electricity and magnetism are not related.
Moving magnets can make electrical currents.
Electricity can create a magnetic field.
Protons and electrons are repelled by magnets.
NEED HELP NOW
Answer:How are electricity and magnetism related?
Moving magnets can make electrical currents.
Electricity and magnetism are not related.
Protons and electrons are repelled by magnets.How are electricity and magnetism related?
Moving magnets can make electrical currents.
Electricity and magnetism are not related.
Protons and electrons are repelled by magnets.
Explanation:
Need help asap!
1. Given that the electronegativity of sulfur (S) is 2.5 and that of silicon (Si) is 1.8, which of the following best describes the chemical bonding in silicon monosulfide (SiS)?
A. ionic: transfer of electrons from silicon to sulfur
B. nonpolar covalent: equal sharing of electrons between silicon and sulfur
C. polar covalent: electrons shared between silicon and sulfur but attracted more to the sulfur
D. polar covalent: electrons shared between silicon and sulfur but attracted more to the silicon
2. Which of the following is a molecular compound?
A. Mg3N2
B. NH3
C. AlCl3
D. LiBr
3. Potassium (K) reacts with a certain nonmetallic element (Z) to form a compound with the general formula KZ; where element Z is a diatomic gas at room temperature. What is element Z?
A. Oxygen
B. Fluorine
C. Nitrogen
D. Hydrogen
Answer: 1. C. polar covalent: electrons shared between silicon and sulfur but attracted more to the sulfur
2. B) [tex]NH_3[/tex]
3. B) Fluorine
Explanation:
1. A polar covalent bond is defined as the bond which is formed when there is a difference of electronegativities between the atoms.
Electronegativity difference = electronegativity of sulphur- electronegativity of silicon = 2.5 -1.8 = 0.7
Thus as electronegativity difference is less than 1.7 , the cond is polar covalent and as electronegativity of sulphur is more , the electrons will be more towards sulphur.
2. A molecular compound is usually composed of two or more nonmetal elements. Example: [tex]NH_3[/tex]
Ionic compound is formed by the transfer of electrons from metals to non metals. Example: [tex]Mg_3N_2[/tex] , [tex]AlCl_3[/tex] and [tex]LiBr[/tex]
3. For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.
Here K is having an oxidation state of +1 and as the compound formed is KZ, the oxidation state of non metallic element Z should be -1. Thus the element Z is flourine which exists as diatomic gas [tex]F_2[/tex]
Sulfur dioxide (SO2) is an unwelcome result
of burning soft coal in power plants. Some
of the SO2 ends up as sulfuric acid in acid
precipitation. The net reaction is
2 SO2(g) + O2(g) + 2 H2O(l) —— 2 H2SO4(l)
What mass in grams of SO2 is needed to
react with 1771 g of O2?
Answer in units of g.
Answer:
I believe it is 1771 divided by 4
Explanation:
How many grams are in 4.58x1023 atoms of oxygen?
Which macromolecules break apart by hydrolysis?
Answer:
Dehydration synthesis reactions build molecules up and generally require energy, while hydrolysis reactions break molecules down and generally release energy. Carbohydrates, proteins, and nucleic acids are built up and broken down via these types of reactions, although the monomers involved are different in each case.
Explanation:
PLEASE HELP PLEASE LLEASE HELP, WILL MARK BRAINLIEST!!!
Which of the following elements will NOT reach an octet when in a bond?
Answer:
Hydrogen
Explanation:
Analysis of an unknown substance indicates that it is a brittle solid. It acts as an electrical insulator (does not conduct) as a solid but conducts electricity when melted. Which of the following substances would have these characteristics?
a. HCl
b. Al
c. KBr
d. SiF4
e. I2
Answer:
KBr
Explanation:
A metal has a very high melting point. Aluminum is a metal.
Ionic solids do not conduct electricity in the solid state. However, when the solids are melted, they conduct electricity.
KBr is an ionic substance, it can only conduct electricity in molten form because the ions are locked up in the solid.
What is the ratio of hydrogen atoms to oxygen atoms in a water molecule?
