Answer:
strong base
Explanation:
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A student determines that the mass of a sample of aluminum is 8.3 g. How many moles are in the sample?
Answer:
0.307
Explanation:
use the formula of n=mass /molar mass
Which element contains four electrons in its third and outer main energy level?
Answer:
valence electrons
Explanation:
The valence electrons are the outer most electrons and the principal energy level in which they belong will vary for .
The chemical element which contains four (4) electrons in its third and outer main energy level is: Silicon (Si).
An electron shell can be defined as the outermost shell of an atom of a chemical element around the atomic nucleus.
Hence, an electron shell is an orbital that is typically accompanied by electrons around the nucleus of an atom.
A sublevel is also referred to as an orbital and it can be defined as an energy level that is associated with the electrons found outside the atomic nucleus.
In Chemistry, there are four main (4) types of sublevel and these are:
s orbital (sublevel): it has one (1) orbital i.e 1s.p orbital (sublevel): it has three (3) orbitals.d orbital (sublevel): it has five (5) orbitals.f orbital (sublevel): it has seven (7) orbitals.In the third (3rd) energy level, there are only three (3) sublevels and these are; s, p and d sublevels.
Silicon is a chemical element that is found in group (4) of the periodic table because it has four (4) electrons in its third and outermost shell.
In its ground state, Silicon (Si) contains the following number of electrons:
Two electrons in its first (n = 1) energy level. Eight electrons in the second (n = 2) energy level.Lastly, it contains four (4) electrons in its third (n = 3) and outer main energy level.Read more: https://brainly.com/question/18214726
Calculate the final volume of a solution prepared by diluting a 4.0 M solution with a volume of 7.0 mL to 0.80 M in milliliters.
Answer:
Explanation:
Let the final volume be v .
from the formula
S₁ V₁ = S₂V₂
4 x 7 = .8 x V₂
V₂ = 35 mL
Final volume of the solution will be 35 mL .
How many molecules are there in 985 mL of nitrogen at 0.0 degrees C and 1.00x10^-6 mm Hg?
(It would be better if work or steps to solve problem are given but if not its fine).
Answer:
3.48 x 1013 N2 molecules
step-by-step explanation:
Lets set up our equation first
P = 1.00 x 10-6 mm Hg T = 0.0° C + 273 = 273 K
We are given the V = 985 mL ,
R = 0.0821 L·atm/mol·K
Now use the ldeal gas law, but we are solving n, amount of substanvce
PV = nRT, we will change this equation to ;
n = PV/RT
n = 1.00 x 10-6 mm x 1 atm/760 mm x 985 mL x 1 L/103
mL/
(0.0821 L·atm/mol·K x 273 K) = 5.78 x 10-11 moles N2
nmolecules = 5.78 x 10-11 moles N2 x 6.02 x 1023 N2 molecules/1 mol N2
Item 4
Which statement is one of the three parts of cell theory?
Cell organelles can be membrane-bound or not membrane-bound.
Cells make up tissues, tissues make up organs, organs make up systems, systems make up organisms.
The smallest living things are single cells, and cells are the functional units of multicellular organisms.
There are three types of cells, prokaryotic, eukaryotic plant, and eukaryotic animal.
The smallest unit of an element that can exist either alone or in combination with other such particles of the same or different elements is the
А.
electron
B
proton
neutron
D
atom
Answer:
The answer is D - Atom
The smallest unit of an element that can exist either alone or in combination with other such particles of the same or different elements is the atom.
What is an atom?
An atom is defined as the smallest unit of matter which forms an element. Every form of matter whether solid,liquid , gas consists of atoms . Each atom has a nucleus which is composed of protons and neutrons and shells in which the electrons revolve.
The protons are positively charged and neutrons are neutral and hence the nucleus is positively charged. The electrons which revolve around the nucleus are negatively charged and hence the atom as a whole is neutral and stable due to presence of oppositely charged particles.
Atoms of the same element are similar as they have number of sub- atomic particles which on combination do not alter the chemical properties of the substances.
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Particle motion in ice is __________than partlice motion in water.
1. faster
2. slower
3. the same
Answer:
1. Faster
Explanation:
Choose all the answers that apply.
Ionic compounds _____.
-do not dissolve in water
-have high melting points
-have low melting points
-dissolve easily in water
-conduct electricity when melted
Answer:
high melting points, dissolve easily in water, conduct electricity when melted.
Explanation:
I'm pretty sure
There are approximately 250 million passenger vehicles in the United States. If each is driven 25,000 km per year, calculate the total mass of CO, NOx and HC emitted in 1970 if all vehicles just meet the government standard at that time. Please find the standard values in textbook. (Please round up to 3 decimal points and use 'E' for exponent)
Answer:
CO = 1.320 x 10¹¹ Kg
NOx = 1.942 x 10¹⁰ Kg
HC = 1.592 x 10¹⁰ Kg
Explanation:
Given that;
there are approximately 250 million passenger vehicles
each is driven 25,000 km per year which is 15534.28 miles per year
In 1970, the vehicular emission norms are;
CO = 34 g/mile , NOx = 5 g/mile , HC = 4.1 g/mile
so emission of CO in 1970 is;
250000000 × 15534.28 × 34 g
= 1.320 x 10¹⁴ g
= 1.320 x 10¹¹ Kg
Also, emission of NOx in 1970
250000000 × 15534.28 × 5 g
= 1.9417 x 10¹³ g
= 1.942 x 10¹⁰ Kg
emission of HC in 1970
= 250000000 × 15534.28 × 4.1 g
= 1.5922 x 10¹³ g
= 1.592 x 10¹⁰ Kg
If 1.4434 moles of H2O are produced, how many moles of N2 will also be produced?
Answer:
1 gram of N2 is equal to 0.035697202053303 mole. i dont know the rest but intried to help
. hopefully this will give you someone else a starting point. goodluck
If 200.00 mL of a solution of sugar and water contains 0.0025 moles of sugar, what is the concentration of the solution in units of moles per unit volume? Round decimals to the nearest thousandth where applicable. Do not include trailing zeros in decimal answers (e.g., 0.05 instead of 0.050).
Answer:
0.013 mol/L
Explanation:
Molarity, which is molar concentration or moles per unit volume, can be calculated using the formula:
M = n/V
Where; M = Molar concentration of solution
n = number of moles of solute
V = Volume of solvent
n = 0.0025 moles of sugar
V = 200.00mL of solution
Since 0.001L = 1mL
200mL = 0.200L
Therefore, M = n/V
M = 0.0025/0.200
M = 0.0125 mol/L
Round up to the nearest thousandth ~ 0.013mol/L
what is functional group of ethers?
Answer:
Explanation:The ether functional group consists of an oxygen atom that forms single bonds with two carbon atoms
How would you calculate an object's mechanical energy?
a. Add its kinetic and potential energies. b. Multiply its kinetic and potential energies.
c. Subtract its kinetic energy from its kinetic energy.
d. Subtract its potential energy from its kinetic energy.
Answer:
You would add its kinetic and potential energies.
Explanation:
Hope this helps!! :)
Answer:
A) Add its kinetic and potential energies
Explanation:
I got it right on Edge 2022
When 28.0 g of acetylene reacts with hydrogen, 24.5 g of ethane is produced. What is the percent yield of C2H6 for the reaction?
C2H2(g) + 2H2(g) → C2H6(g)
Answer:
[tex]Y=75.6\%[/tex]
Explanation:
Hello.
In this case, since no information about the reacting hydrogen is given, we can assume that it completely react with the 28.0 g of acetylene to yield ethane. In such a way, via the 1:1 mole ratio between acetylene (molar mass = 26 g/mol) and ethane (molar mass = 30 g/mol), we compute the yielded grams, or the theoretical yield of ethane as shown below:
[tex]m_{C_2H_6}^{theoretical}=28.0gC_2H_2*\frac{1molC_2H_2}{26gC_2H_2}*\frac{1molC_2H_6}{1molC_2H_2} *\frac{30gC_2H_6}{1molC_2H_6}\\ \\m_{C_2H_6}^{theoretical}=32.3gC_2H_6[/tex]
Hence, by knowing that the percent yield is computed via the actual yield (24.5 g) over the theoretical yield, we obtain:
[tex]Y=\frac{24.5g}{32.3g}*100\%\\ \\Y=75.6\%[/tex]
Best regards.
List the steps in the water cycle, in the correct order?
write the equation for the beta decay of 53/26 FE
Answer:
53/26Fe = 0/-1,B + 53/27 Co
Determine whether the disruption of the bonds or attractions occurs during protein hydrolysis or protein denaturation.
Answer:
The disruption of the bonds or attractions occurs during protein hydrolysis which results in the loss for the primacy structure. The peptide bonds is the bond affected in this scenario.
The disruption of the bonds however only exist in the process of denaturation and this results in a change in the confirmation which could be secondary, tertiary, and quaternary structural related. And example of the bonds affected include salt bridges, disulfide bridges, hydrogen bonds etc.
calculate the mol fraction of ethanol and water in a sample of rectified spirit which contains 95% of ethanol by mass
Answer:
We are given that there is 95% ethanol by mass in rectified spirit
so, we can say that in a 100g sample, we have 95 grams of ethanol and 5 grams of water
we will find the number of moles of ethanol and water in 100g solution of rectified spirit and use that to calculate the mole fraction
Moles of Ethanol:
Molar mass of ethanol = 46 grams / mol
Number of moles = Given mass / molar mass
Number of moles = 95 / 46
Moles of Ethanol = 2 moles (approx)
Moles of Water:
Molar mass of water = 18 grams per mol
Number of moles = Given mass / molar mass
Moles of water = 5 / 18
Moles of water = 0.28 moles (approx)
Mole Fractions:
Mole fraction of a specific compound is the number of moles of that compound divided by the total number of moles in the solution
Mole fraction of Ethanol:
Moles of ethanol / (moles of ethanol + moles of water)
2 / (2 + 0.28)
2 / (2.28) = 0.9 (approx)
Mole fraction of Water:
Moles of water / (Moles of ethanol + moles of water)
0.28 / (2 + 0.28)
0.28 / (2.28) = 0.1 (approx)
If your hypothesis is incorrect you should...
An atom of beryllium has 4 protons, 4 electrons, and 5 neutrons. What is its mass number?
Answer:
D. 9.
Explanation:
Mass number of an atom is the sum of the proton number and neutron number. For Be, the protons are 4 and neutrons are 5. So, we get 9 by adding them.
Help :( the blue boxes are clickable
Answer:
I am sure they are why won't they
Why must you avoid touching the gas Spectrum tubes?
atmospheric pressure at elevations of 8000 feet averages about 0.72 atmospheres. Would a cabin pressurized at 500 mm hg meet federal standards
Answer:
Yes, but it must be kept at that value and do not let it to decrease more.
Explanation:
Hello.
In this case, in order to substantiate whether the cabin meet the federal standards, we need to convert the 500 mmHg to atm and compare the result with 0.72 atm by knowing that 1 atm equals 760 mmHg:
[tex]500mmHg*\frac{1atm}{760mmHg} \\\\=0.66atm[/tex]
Thus, since 0.66 atm is 0.06 atm away from the federal standard we can infer that it may meet the federal standard, however, it would not be recommended to let the pressure decrease more than that.
Yes, the cabin pressurized at 500 mm hg meets federal standards.
1 atm is approximately equal to 760 mm Hg. Therefore, the pressure is:
500 mm Hg / 760 mm Hg/atm ≈ 0.65789 atm
So, the cabin pressure of 500 mm Hg is approximately 0.65789 atmospheres. If the atmospheric pressure at an elevation of 8000 feet averages about 0.72 atmospheres, then the cabin pressure of 0.65789 atmospheres would be lower than the ambient atmospheric pressure.
To meet federal standards, cabin pressure should be maintained at an equivalent pressure that allows occupants to breathe comfortably.
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6 CO2 + 6 H2O
How many atoms of each element are in
the equation?
Answer:
There are 6 Carbon dioxides, and 6 waters, but there are 6 carbons, 18 oxygens, and 12 hydrogens.
Explanation:
Answer:
6 carbon atoms
18 oxygen atoms
12 hydrogen atoms
What is the atomic number of arsenic (As)?
O A. 33
O B. 15
C. 75
D. 4
SUB
Answer:
33
Explanation:
A black object appears black because it reflects all light , and does not absorb any light. True or False
Answer:
False
Explanation:
It is the other way round, a black object appears black because it absorbs all the wavelength of light and does not reflect any light.
A black bucket will appear black because, it absorbs all wavelength of light incident on it. No other wavelength is reflected from the surface of the body. A black color suggests that a body is not reflecting any color. Instead such a body absorbing all the colors. For a white object, they reflect all the wavelength that is incident upon them.What is anology?
What is microscope?
where are electrons found in an atom
Answer:
The electrons are found on the outer shell of the atom.
Explanation:
Please tell me the answers to A, B, and C
Answer:
A=element
B=compond
C=solution
Identify the correct net ionic equation for the reaction that occurs when solutions of Pb(NO3)2 and NH4Cl are mixed.
Answer:
Pb2+(aq) + 2Cl–(aq) ----> PbCl2(s)
Explanation:
The net ionic equation shows the main reaction that takes place in a system. Hence, a net ionic equation focusses only on those species that actually participate in the reaction.
For the reaction between Pb(NO3)2 and NH4Cl , the net ionic equation is;
Pb^+(aq) + 2Cl^-(aq) ---> PbCl2(s)
The correct net ionic equation for the reaction that occurs when solutions of Pb(NO₃)₂ and NH₄Cl are mixed is
Pb⁺(aq) + 2Cl¯(aq) —> PbCl₂(s)To know the the correct net ionic equation for the reaction that occurs when solutions of Pb(NO₃)₂ and NH₄Cl are mixed, we shall write the net ionic equation for the reaction. This is illustrated below:
Pb(NO₃)₂(aq) —> Pb⁺(aq) + NO₃¯(aq)
NH₄Cl(aq) —> NH₄⁺(aq) + Cl¯(aq)
Pb(NO₃)₂(aq) + NH₄Cl(aq) —>
Pb⁺(aq) + NO₃¯(aq) + NH₄⁺(aq) + Cl¯(aq) —> PbCl₂(s) + NO₃¯(aq) + NH₄⁺(aq)
Cancel the spectator ions (i.e NO₃¯ and NH₄⁺) and write 2 before Cl¯ to obtain the net ionic equation as shown below:
Pb⁺(aq) + 2Cl¯(aq) —> PbCl₂(s)Thus, the correct net ionic equation for the reaction that occurs when solutions of Pb(NO₃)₂ and NH₄Cl are mixed is
Pb⁺(aq) + 2Cl¯(aq) —> PbCl₂(s)Learn more: https://brainly.com/question/21883718