Answer:
A. An Atom
Explanation:
An atom is the smallest particle of an element, having the same chemical properties as the bulk element.
An atom of calcium is the smallest particle of calcium that has the same chemical properties of calcium.
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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60
х
8
у
x=
04
09
O 16
Answer:
The answer is 16
Explanation:
It needs to be hald of the medium so devide the 2 numbers
Which of the following best explains how the results of Rutherford’s experiment affected Thomson’s widely-accepted atomic model?
Explanation:
Thomson's suggested the plum pudding model of the atom in which the atomic space is made up of electrons surround by positive charges.
Rutherford in his gold foil experiment revised the plum pudding model of the atom;
He discovered that most of the alpha particles passed through the foil while a few of them were deflected back. To explain this observation, he suggested the atomic model of the atom. In this model, an atom is made up of a small positively charged center where nearly all the mass is concentrated. Surrounding the nucleus is the extranuclear part made up of electrons.to make a solute dissolve more quikly in a solvent wich whould you do? a. stir it in cold water b.stir it in warm water c.solvent d.lets the solute settle down d. nothing to do with the solute?
Answer:
b.stir it in warm water
Explanation:
the slobility will be faster in the high temperture
23.1 g of HCl (a strong acid) is added to water to make 1250 mL of solution. Calculate [H3O+] and pH of the solution
Answer:
Following are the solution to this question:
Explanation:
[tex]\to HCl \ mol = \frac{23.1 \ g}{36.5 \frac{g}{mol}} = 0.633 \ mole\\\\\\\to HCl \ molarity = \frac{ 0.633 \ mole }{1.25 L} \\\\[/tex]
[tex]=0.5064 \ m[/tex]
[tex]HCl +H_2O \longrightarrow H_3O^{+} + Cl^{-}\\\\\\[/tex]
[tex][H_3O^{+}] =[HCl] \\\\\to [H_3O^{+}] =0.5064 \ m \\\\\to PH =-\log [H_3O^{+}] \\\\[/tex]
[tex]= -\log (0.5064)\\\\= 0.295 \\\\=0.3[/tex]
Scenario Three: Carbon dioxide emissions increase
• Set the carbon dioxide emissions rate to 9.8 gigatons.
• Set the time step size to 10 years.
• Select the step forward button once.
• Increase the carbon dioxide emissions by 0.2 and press step forward.
• Continue stepping forward once, increasing the carbon emissions each time, until you reach 2110.
• Record the data in the table below.
Maintain carbon dioxide emissions at 9.8 for the rest of scenario one.
2020 9.8 58
2030 9.8 58.5
2040 9.8 58.9
2050 9.8 59.1
2060 9.8 59.5
2070 9.8 59.8
2080 9.8 60
2090 9.8 60.1
2100 9.8 60.5
2110 9.8 60.9
I need HALP so yea halp mee please
Blair bought a hutch for her desk that was 23 inches long. The box said that the
hutch was 25 inches long. What was the percent error of the hutch?
Many materials, such as rocks, expand (get larger) when they are heated and contract (shrink) when they are cooled. This change
in size can cause cracks to form and break large rocks into smaller pieces.
In this example, what is caused by heating and cooling?
OA. decay
ОВ.
weathering
OC.
erosion
OD
earthquakes
Answer:
OB: weathering
Explanation:
the cycle of heating and cooling causes stresses called thermal fatigue, this causes the material to break down. In hand, weathering is a physical and chemical process that causes rocks and minerals on the Earth's surface to break down and decompose. Therefore, this matches the process you have described.
Answer:
weathering fun way to imagen it: just imagen u saw ur worst enemie and pretende it is the rock and the wind and ice and water are ur best friends THEN BAM wind and ice and water(ur best friends) make the rock(worst enemie) to dust :D
3. Theoretically how many grams of magnesium is required to produce to 5.0 g of
Magnesium oxide?
Answer:
3grams
Explanation:
The reaction for the production of Magnesium dioxide will be
Mg + O2 → MgO
we have 5g of MgO (molar mass 40g)
no of moles of MgO = 5/40 = 0.125
Using unitary method we have
1 mole of Mg require 1 mole of MgO
0.125 Mole of MgO = 0.125mole of Mg
n = given mass /molar mass
0.125 = mass / molar mass
mass = 0.125* 24 = 3grams
at what pressure does water boil at room temperature 25 ec
Answer: approximately 100 degrees Celsius
plz help me.......
questiion: Following are the correct statements for actual yield except
1:amount of product obtained in a chemical reaction
2:always less than theoretical yield
3:none
4:product calculated from the balanced chemical equation
give the balanced chemical reaction for the preparation of black oxide from blue vitriol
Answer:
Blue vitriol is crystal copper sulphate
Explanation:
The black oxide is the higher oxide of Copper i.e Cu. It is also called as tenorite. It is solid black in color. It is formed by heating copper with air.
[tex]$2Cu +O_2 \rightarrow 2CuO$[/tex]
Blue vitriol is the crystalline form of copper sulphate. It is also known as copper (II) sulphate.
When heating, the blue vitriol undergoes various steps of changes to the black oxide of copper.
The chemical reaction is --
[tex]$CuSO_4 \cdot5H_2O \rightarrow CuSO_4\cdot 3H_2O {\rightarrow} CuSO_4\cdot H_2O \rightarrow CuSO_3 \rightarrow CuO +SO_2+O_2[/tex]
A 75 mL solid is estimated by a student to be 81 mL. Calculate the percent error.
Answer:
8 %Explanation:
The percentage error of a certain measurement can be found by using the formula
[tex]P(\%) = \frac{error}{actual \: \: number} \times 100\% \\ [/tex]
From the question
error = 81 - 75 = 6 mL
actual volume = 75 ml
We have
[tex]p(\%) = \frac{6}{75} \times 100 \\ = \frac{2}{25} \times 100 \\ = 2 \times 4 \\ = 8 \: \: \: \: \: \: \: \: [/tex]
We have the final answer as
8 %Hope this helps you
12.5 mL of 6.0 M KCl is diluted to make a 1.5 L solution. The molarity of the dilution solution is ___ M. (Round atomic masses to the nearest whole number. Include 2 sig figs total in your answer.)
The molarity of the dilution solution is 0.050 M
Further explanationMolarity is a way to express the concentration of the solution
Molarity shows the number of moles of solute in every 1 liter of solute or mmol in each ml of solution
[tex]\large{\boxed {\bold {M ~ = ~ \frac {n} {V}}}[/tex]
Where
M = Molarity
n = Number of moles of solute
V = Volume of solution
Dilution formula :
[tex]\tt M_1.V_1=M_2.V_2[/tex]
M₁=6 M
V₁=12.5 ml
V₂=1.5 L=1500 ml
[tex]\tt 6\times 12.5=M_2\times 1500\\\\M_2=\dfrac{6\times 12.5}{1500}=0.05~M\\\\for~sig.fig\rightarrow 0.050~M[/tex]
What is Zaitsev's rule?
Answer:
dear I think this help u
Explanation:
In organic chemistry, Zaitsev's rule is an empirical rule for predicting the favored alkene product in elimination reactions. While at the University of Kazan, Russian chemist Alexander Zaitsev studied a variety of different elimination reactions and observed a general trend in the resulting alkenes.
The phase of the moon you see depends on
Answer:
The phases of the Moon depend on the moon's position compared to the Earth and the Sun. Remember that the moon revolves around the Earth. As the moon goes around the Earth, half of the moon is always illuminated by the Sun.
What are two cases when a cell must use active transport in order to move materials?
Answer:
A cell must use active transport in order to move materials in the process Phagocytosis and Pinocytosis
Calculate molecules in 1dm^3 of oxygen
Number of molecules in 1 dm³ Oxygen = 2.71 x 10²²
Further explanationConditions at T 0 ° C and P 1 atm are stated by STP (Standard Temperature and Pressure). At STP, Vm is 22.4 liters/mol.
The mole is the number of particles contained in a substance
1 mol = 6.02.10²³
1 dm³ of oxygen = 1 L Oxygen
mol Oxygen :[tex]\tt \dfrac{1}{22.4}=0.045`mol[/tex]
molecules of Oxygen :n=mol=0.045
No = 6.02.10²³
[tex]\tt N=n\times No\\\\N=0.045\times 6.02\times 10^{23}\\\\N=2.71\times 10^{22}[/tex]
why do we need air? If you know please answer this
Answer:
I found this on the internet People need to breathe, and so do lots of other animals—and plants! Breathing is part of a process called respiration. During respiration, a living thing takes in oxygen from the air and gives out carbon dioxide.
Explanation:
10 Interesting Things About Air | NASA Climate Kidsclimatekids.nasa.gov › 10-things-air
Your welcome!
to breath
with out air we can't live here
3. What is the total mass of Zinc in ZnCI.?
Which statement describes an example of a chemical property of a metal statue?
O It is metal.
O It can tarnish.
OIt is solid.
OIt is shiny.
Answer:
The answer is "it can tarnish"
Explanation:
The statement describes an example of a chemical property of a metal statue is that it can tarnish.
Chemical properties are defined as those properties which become evident during or after a chemical reaction has taken place.
These properties cannot be determined externally just by viewing the substance ,these change immensely after a substance undergoes a chemical change.These are used for identification of unknown substances and used for building up chemical classifications.
The major chemical properties include flammability,toxicity,reactivity,acidity and heat of combustion.For a chemical property to be apparent , it is necessary that the structure of the substance is altered.
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Weathering is a constructive process.
True or false
Answer: true
Explanation: Collection and analysis of data indicates that constructive forces include crustal deformation, faulting, volcanic eruption and deposition of sediment, while destructive forces include weathering and erosion.
How much heat is required to raise the temperature of 91.5 g of water from its melting point to its boiling point? Express your answer numerically in kilojoules. Can someone answer this for me in decimal form?
Answer:
38.2836 kJ
Explanation:
Mass = 91.5g
Initial Temperature = melting point = 0 C = 273 K (upon converting to kelvin)
Final Temperature = Boiling point = 100 C = 373 K
Heat = ?
They are related by the equation;
H = mCΔT
ΔT = Final - Initial Temperature = 373 - 273 = 100 K
C = specific heat capacity = 4.184 J /gK
H = 91.5 * 4.184 * 100
H = 38283.6 J
To convert to kilojoules, divide by 1000. This leaves us with;
H = 38283.6 / 1000 = 38.2836 kJ
1. A physician ordered 2.0 milligrams tetracycline to be given to a patient. If the tetracycline was available as 0.75 mg/mL of solution, how many milliliters would you give to the patient
Answer:
2.67 mL
Explanation:
The following data were obtained from the question:
Mass of tetracycline = 2 mg
Density of tetracycline = 0.75 mg/mL
Volume of tetracycline =?
We can obtain the volume of the tetracycline that should be given to the patient by applying the following equation:
Density = mass /volume
0.75 = 2 / volume
Cross multiply
0.75 × Volume = 2
Divide both side by 0.75
Volume = 2/0.75
Volume = 2.67 mL
Therefore, the volume of the tetracycline that should be given to the patient is 2.67 mL
How many moles of KCI would be dissolved in 4 L of water to make a 2 M
solution?
1
A.
mole
B. 2 moles
C. 8 moles
D. 4 moles
Answer:
C. 8 Moles
Explanation:
2.00 mL of a 12.00 M HCL solution was reacted with 0.0450 grams of magnesium.?
Which reactant is the limiting reactant? Mathematically document your answer.
Answer:
Magnesium Mg will be the limiting reagent .
Explanation:
The limiting reagent is one that is first consumed in its entirety, determining the amount of product in the reaction. When the limiting reagent ends, the chemical reaction will stop.
In other words, the limiting reagent is that reagent that is consumed first in a chemical reaction, determining the amount of products obtained. The reaction depends on the limiting reagent, because the other reagents will not react when one is consumed.
In this case, the balanced reaction is:
Mg + 2 HCl ⇒ MgCl₂ + H₂
You know tha 2.00 mL of a 12.00 M HCl solution was reacted with 0.0450 grams of magnesium.
Being Molarity (M) the number of moles of solute that are dissolved in a certain volume, calculated by the expression:
[tex]Molarity=\frac{number of moles of solute}{volume}[/tex] ( Molarity is expressed in units [tex]\frac{moles}{liter}[/tex])
then the number of moles can be calculated as:
number of moles of solute=molarity* volume
So, being:
molarity= 12 Mvolume= 2 mL= 0.002 L (being 1,000 mL= 1 L)The number of moles of HCl that react is:
number of moles of HCl= 12 M*0.002 L= 0.024
On the other hand, since the molar mass of magnesium is 24.305 g / mol, then if 0.0450 grams of magnesium react, it indicates that they must react:
[tex]0.0450 grams*\frac{1 mol}{24.305 grams} = 0.00185 moles[/tex]
To determine the limiting reagent, it is possible to use the reaction stoichiometry of the reaction (that is, the relationship between the amount of reagents and products in a chemical reaction), and a simple rule of three as follows: if by stoichiometry 1 mole of Mg reacts with 2 moles of HCl, how much moles of Mg will be needed if 0.024 moles of HCl react?
[tex]moles of Mg=\frac{0.024 moles of HCl*1 moles of Mg}{2 moles of HCl}[/tex]
moles of Mg= 0.012
But 0.012 moles of Mg are not available, 0.00185 moles are available. Since you have less moles than you need to react with 0.024 moles of HCl, magnesium Mg will be the limiting reagent .
Preparation of ethanoic acid from 1,1,1-trichloroethane
What are things animals might do to survive?
Answer:
Animals need food, water, shelter, and space to survive. Herbivores can live only where plant food is available. Carnivores can live only where they can catch their food. Omnivores can live in many places because they eat both plants and animals.
Which isomer of 1-bromo-4-tert-butylcyclohexane reacts faster when refluxed with potassium tert-butoxide?
Answer:
See explanation.
Explanation:
Since potassium tert-butoxide is a strong bulky base, we expect that an elimination reaction predominates.
This reaction is expected to occur by E2 mechanism. The cis isomer of 1-bromo-4-tert-butylcyclohexane is known to react faster by E2 mechanism because it fulfills the anticoplanar arrangement required for for E2 mechanism, where the leaving group and adjacent proton must be anti to each other and in the same plane. The trans isomer can not fulfill this requirement.
What is the new concentration for 25mL added to 135mL of .150M
Answer:
The concentration for 25 mL is 0.81 M
Explanation:
Given data:
Initial volume = 135 mL
Initial molarity = 0.150 M
New volume added = 25 mL
Concentration for 25 mL = ?
Solution:
M₁V₁ = M₂V₂
0.150 M × 135 mL = M₂ × 25 mL
M₂ = 0.150 M × 135 mL / 25 mL
M₂ = 20.25 M.mL/25 mL
M₂ = 0.81 M
The concentration for 25 mL is 0.81 M.