Answer: 20 protons,20 electrons and 21 neutrons
Explanation: because the number of protons is the same as the atomic number, and if the atom is neutral it has the same number of protons and electrons. if the mass number is 41 it means that there are 21 neutrons because to find the mass number you have to add protons and neutrons, so 20 + 21 = 41 and to confirm it the neutrons have been subtracted from the mass number and the atomic number, so 41-20 = 21
Which statement correctly describes a feature of the rock cycle?
PA
Rocks are preserved through the process.
Rocks change from one type to another.
Different rock groups are not related to one another.
Rocks change from one type to another in a specific order.
Answer:
It’s D
Explanation:
Answer:
D Rocks change from one type to another in a specific order.
Explanation:
For each of the compounds, find the length of the longest carbon chain in the box provided.
CH,
CH3 -CH2-CH2-CH2-CH-CH2-CH2 - CH2 - CH3
CH,CH,CH,
HC
CH-CH2-CH3
CH,CH.CHCCH,CH,CH,
1
CH2
H.C CH.CH
CH3
<
Answer:
In First compound the longest chain contains 7 C atoms.
In the Second compound the longest chain contains 9 C atoms.
In the Third compound the longest chin contains 7C atoms.
Explanation:
In first compound the longest chain contains 7 carbon atoms.In the second compound the longest chain contains 9 carbon atoms.In the third compound the longest chin contains 7 carbon atoms.
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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what is the molar mass of magnesium tartrate
Answer:
172.385 g/mol
Explanation:
Magnesium Tartrate is C4H4MgO6
C - 12.01 g/mol
H - 1.01 g/mol
Mg - 24.305 g/mol
O - 16.00 g/mol
12.01(4) + 1.01(4) + 24.305 + 16(6) = 172.385 g/mol
Answer:
172.38
Explanation:
[tex]C_4H_4MgO_6\\C=12.01\\H=1.01\\Mg=24.30\\O=16.00\\\\4(12.01)+4(1.01)+24.30+6(16.00)\\48.04+4.04+24.30+96\\=172.38[/tex]
C = 12.01
H=1.01
Mg=24.30
O =16.00
4(12.01)+4(1.01)+24.30+6(16.00)
48.04 +4.04+24.30+96
=172.38
What biological sample do home pregnancy tests use to detect pregnancy?
Answer:
The biological sample that pregnancy tests use to detect pregnancy is urine
Answer:
yes
Explanation:
the urine in the the tester will find hormones to determine if pregnant or not
Identify the correct statement regarding the strength of chemical bonds.
Weak bonds require more surface area to form than strong bonds.
A weak bond forms from a smaller change in energy compared to a strong bond.
Strong bonds occur with high temperature and weak bonds with low temperature.
Weak bonds require more heat to form than strong bonds.
Answer:
B.
Explanation:
A weak bond forms from a smaller change in energy compared to a strong bond.
Which is one way that a short-term environmental change will most likely affect organisms within an ecosystem? A)It will lead to larger populations. B)It will lead to speciation. C)It will lead to adaptation. D)It will lead to forced migration.
Answer:
D)It will lead to forced migration.
Explanation:
Forced migration is an involuntary, sudden movement of organisms from one geographical location to another. This is often in response to short term environmental changes such as drought, famine, etc
When an ecosystem suddenly comes under stress due to these short term environmental changes, organisms may not be left with any other choice but to move or go to new locations in the quest for survival. The organisms may not have left the ecosystem in the absence of such short term ecological stress. This is what is meant by forced migration.
Answer:
D forced migration
Explanation:
what is meant by amoeba and what is the name of its parts
Answer:
amoeba is the unicellular organism which can be seen by only microscope but not with our nacked eyes
Answer:
An amoeba often called an amoeboid, is a type of cell or unicellular organism which has the ability to alter its shape, primarily by extending and retracting pseudopods Amoebae do not form a single taxonomic group; instead, they are found in every major lineage of eukaryotic organisms. Amoeboid cells occur not only among the protozoa, but also in fungi, algae, and animals.
name of parts of ameoba
3 parts – the cytoplasm, plasma membrane and the nucleus. The cytoplasm can be differentiated into 2 layers – the outer ectoplasm and the inner endoplasm. The plasma membrane is a very thin, double-layered membrane composed of protein and lipid molecule
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Calculate the payback time if she insulates the loft with 300 mm insulation when: area of loft space = 100m^2 cost of roll of 100 mm thick loft insulation that covers 8.3m^2 = £20 cost of putting the insulation into the loft = £120 savings per year = £80 per 100 mm Payback Time = installation cost divided by annual savings
Answer: Payback time = 0.0075
Explanation: Since payback time is calculated as:
payback time = [tex]\frac{installation cost}{annual savings}[/tex]
First determine the installation cost:
100 mm thick insulation covers 8.3 m². Then 300 mm covers 24.9 m².
To cover 8.3m² costs £20. Then, the cost to cover 24.9 m² is:
cost = [tex]\frac{20*24.9}{8.3}[/tex]
cost = £60
The cost of putting the insulation is £120, so the total cost is:
total cost = £60 + £120
total cost = £180
Savings per year per 100 mm thick is £80. For 300 mm, the value of annual savings is:
savings = [tex]\frac{300*80}{100}[/tex]
savings = 240
payback time = [tex]\frac{installation cost}{annual savings}[/tex]
payback time = [tex]\frac{180}{240}[/tex]
payback time = 0.75
which of the following us not a property of salt in the ionic and covalent properties lab
Explanation:
I think Low melting point
because NaCl (salt has mp 801 degC)
Water has mp 0 degC
What mass of nickel (Ni) is in a 2.4 Kg sample of propanol if the concentration is 20 ppb ? (atomic mass of Ni = 58.69)
Answer:
The mass of nickel is 48μg
Explanation:
Parts per billion is a way to describe small concentrations and is defined as the ratio between μg of solute and kg of solvent.
If a solution of nickel in propanol is 20ppb, contains 20μg of nickel in 1 kg of propanol.
Thus, a sample of 2.4kg of propanol will contain:
2.4kg × (20μg nickel / 1kg) = 48μg nickel
The mass of nickel is 48μgTwo oxide of sulphur,A and B were analyzed and the results obtained showed that in oxide A,3.50g of sulphur combined with 6.00g of oxygen and in oxide B,2.80g of sulphur combined with 9.55g.Show that this result illustrate the law of multiple proportion
Answer:
See Explanaton
Explanation:
The law of multiple proportions states that when two same elements form more than a compound, the different masses of one element that combine with the same mass of the other element are in the ratio of small whole numbers.
Oxide A
3.50g of sulphur combined with 6.00g of oxygen
Oxygen:Sulphur = 6 : 3.5
Oxide B
2.80g of sulphur combined with 9.55g
Oxygen : Sulphur = 9.55 : 2.8
Therefore:
The ratio of Oxygen to Sulphur in Oxides A and B is:
[tex]\dfrac{\text{Oxygen}}{\text{Sulphur}} \implies \dfrac{6}{3.5}:\dfrac{9.55}{2.8} = \dfrac{1.7}{1}:\dfrac{3.4}{1}=1:2[/tex]
Ratio of Oxygen=1:2
There is exactly twice in Oxide B as in Oxide A.
This result illustrates the law of multiple proportions.
Which refers to the density of the medium’s particles at the compression of a sound wave? A.amplitude B.pitch C.volume D.wavelength
Answer:
A is the answer.
Explanation:
The sound wave is a longitudinal wave which travels in the form of compression and rarefaction . The point where the particles are closer to each other is called compression and the point where the particles are far apart from each other is called rarefaction.
Answer:
Amplitude
Explanation:
Amplitude describes the displacement of the medium's particles. The higher the amplitude, the more dense it is, and the lower the amplitude, the less dense it is.
Pitch is incorrect because it describes the sound
Volume is incorrect because it describes the sound.
Wavelength is incorrect because it describes the distance between a period of a wave.
Phloem contains specialized cells that move sugars and other nutrients both
up and down in plants. Which object is the best model of one of these cells?
A. Water balloon
Answer:Drinking straw
Explanation: my quiz said so
The object that represents the best model of one of the phloem cells is the drinking straw.
What is Phloem?Phloem may be defined as a type of vascular tissue in plants that significantly conducts the passage of sugars and other metabolic products from the leaves to the roots. This mediates the migration of sugar which is synthesized in the leaves during photosynthesis.
Apart from this, the phloem also regulates the movement of nutrients from the roots to the upper part of the body. This function of phloem cells shares homology with the object known as a drinking straw that mediates the transport of any fluid in both directions.
Therefore, a drinking straw is an object that represents the best model of one of the phloem cells.
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Your question seems incomplete. The most probable complete question is as follows:
Can openerWater balloonDrinking StrawKitchen strainerAfter 273 m3 of ethylene oxide at 748 kPa and 525 K is cooled to 293 K, it is allowed to expand to 1100. m3. The new pressure is _____kPa
Answer:
[tex]\large \boxed{\text{104 kPa}}[/tex]
Explanation:
To solve this problem, we can use the Combined Gas Laws:
[tex]\dfrac{p_{1}V_{1} }{n_{1}T_{1}} = \dfrac{p_{2}V_{2} }{n_{2}T_{2}}[/tex]
Data:
p₁ = 748 kPa; V₁ = 273 m³; n₁ = n₁; T₁ = 525 K
p₂ = ?; V₂ = 1100. m³; n₂ = n₁; T₂ = 293 K
Calculations:
[tex]\begin{array}{rcl}\dfrac{p_{1}V_{1}}{n_{1} T_{1}} & = & \dfrac{p_{2}V_{2}}{n_{2} T_{2}}\\\\\dfrac{\text{748 kPa}\times \text{273 m}^{3}}{n _{1}\times \text{525 K}} & = &\dfrac{p_{2}\times \text{1100. m}^{3}}{n _{1}\times \text{293 K}}\\\\\text{390.0 kPa} & = &3.754{p_{2}}\\p_{2} & = & \dfrac{\text{390.0 kPa}}{3.754}\\\\ & = & \textbf{104 kPa} \\\end{array}\\\text{The new pressure is $\large \boxed{\textbf{104 kPa}}$}[/tex]
Which consists of only one type of atom?
Answer:
A chemical element
Explanation:
A chemical element consists of only one type of atom.
what is the mass of 1.5 mol of aluminum?
Answer:
40.47 g Al
Explanation:
In 1 mol of Al, there are 26.98 grams of Al, so Al is 26.98 g/mol.
Simply multiply 1.5 by 26.98 to get your answer.
Molecular formula of ammonia
Answer:
NH3 is the molecular formula of ammonia
Explanation:
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A 75 lb (34 kg) boy falls out of a tree from a height of 10 ft (3 m). i. What is the kinetic energy of the boy when he hits the ground? Round your answer to the nearest joule. ii. What is the speed of the boy when he hits the ground? Round your answer to two significant figures. iii. Using the conversion factors of 1 m = 1.094 yd and 1 mi = 1760 yd, calculate the speed of the boy in miles per hour when he hits the ground.
Answer:
Kinetic energy of boy just before hitting the ground is [tex]\approx[/tex]1000 J.
Speed of boy just before hitting the ground is 7.67 m/s
or 17.16 mi/hr.
Explanation:
Given that:
Mass of boy = 75lb = 34 kg
Height, h = 10ft = 3m
To find:
Kinetic energy of boy when he hits the ground.
As per law of conservation of energy The potential energy gets converted to kinetic energy.
[tex]\therefore[/tex] Kinetic energy at the time boy hits the ground = Initial potential energy of the boy when he was at the Height 'h'
The formula for potential energy is given as:
[tex]PE = mgh[/tex]
Where m is the mass
g is the acceleration due to gravity, g = 9.8 [tex]m/s^2[/tex]
h is the height of object
Putting all the values:
PE = [tex]34 \times 9.8 \times 3 \approx 1000\ J[/tex]
Hence, Kinetic energy is [tex]\approx[/tex]1000 J.
Formula for Kinetic energy is:
[tex]KE = \dfrac{1}{2}mv^2[/tex]
where m is the mass and
v is the speed
Putting the values and finding v:
[tex]1000 = \dfrac{1}{2}\times 34 \times v^2\\\Rightarrow v^2 = 58.82\\\Rightarrow v = 7.67\ m/s[/tex]
Given that:
1 m = 1.094 yd and 1 mi = 1760 yd
[tex]\Rightarrow 1609\ m = 1\ mi[/tex]
Converting 7.67 m/s to miles/hour:
[tex]\dfrac{7.67 \times 3600}{1609}=17.16\ mi/h[/tex]
what is Lfusion in the equation Q=mLfusion
Answer:
[tex]L_{\text{fusion}[/tex] is latent heat of fusion.
Explanation:
Latent heat is basically termed as hidden heat. It is defined as the amount of heat required to change 1 g of a substance at the temperature of its melting point from the solid to the liquid state at constant temperature.The formula that relates heat and latent heat of fusion is given by :[tex]Q=mL_{\text{fusion}}[/tex]
Here,
m is mass of substance
[tex]L_{\text{fusion}[/tex] is latent heat of fusion.
Which part of the electromagnetic spectrum is nearest to X-rays? microwaves infrared light gamma rays radio waves
Answer:
The correct answer to the following question will be Option A (Microwaves).
Explanation:
This tends to be a source of radiation, including some signals, infrared radiation, x-rays as well as gamma. This appears to have a diverse variety of uses, involving communications, radar, and scheduling, but best known by most individual people. Sections of society used handheld devices, including tablets, as well as WiFi.The other given choices are not related to the given circumstances. So that option A seems to be the appropriate one.
Answer:
its a
Explanation:
Set up the ion formation equations, with ionization energy values for each electron in the valence layer, of the atoms of the chemical elements below: a) Na z=11 b) Ca z= 20 c) Sr z 38 d) Li z= 3 e) Cs z= 55 f) Be z= 43
Answer:
according to quantum physics newtons 3rd law is in the state of nuclear power things so the answer is c
Explanation:
according to quantum physics newtons 3rd law is in the state of nuclear power things so the answer is c
a heating fan is supplied with 150 j of electricity which is nonverts to 113 j of thermal energy and 37 j of sound energy
How efficient is the heating fan?
Answer:
Heating Fan is 75.33% efficient.
Explanation:
As it is mentioned that the given fan is a HEATING FAN, it means the it is used for provided heat (thermal energy) to the surrounding. Hence, its efficiency depends upon how much heat/thermal energy is provides.
We can state that.
Total Energy provided = 150 J
Useful Energy = 113 J
Wasted Energy = 37 J
The efficiency of the heating fan can be given by following formula:
Efficiency = ( Useful Energy / Total Energy ) × 100
Efficiency = ( 113 J / 150 J) × 100
Efficiency = (0.7533)× 100
Efficiency = 75.33%
how many atoms are contained in 2.70g of aluminum provided that 32g of sulphur equals 6.02 × 10^(23)atoms
Answer:
[tex]1.63 \times {10}^{24} [/tex]
one atom of an element = 6.02 \times {10}^{23} atom
The mass of one atom of sulphur = 32g
The mass of one atom of aluminium = 27g
so one atom of aluminium = 6.02 \times {10}^{23}
27g of AL = 6.02 \times {10}^{23} atom
2.70g of AL = X atoms
Then you cross multiply ........
and get the answer
.
c. Write a complete ionic equation for the reaction and identify the spectator ions.
The required complete ionic equation of the reaction
Pb(NO3)2+2KI---->PbI2+2KNO3 is Pb2+(aq) + 2 I−(aq) → PbI2(s)
What is ionic equation?A chemical equation in which the electrolytes in aqueous solution are expressed as dissociated ions.
Spectator ions in above equation are as follows- K +and NO3−
Define spectator ions.
Ions that are not involved in the actual chemical reaction are called spectator ions.
Net ionic equation of given reaction isPb⁺²+2I ⁻¹⟶PbI₂It shows only the ions which involves in the chemical reaction.
Therefore, K⁺ and NO3⁻ are spectator ions.
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Which of the following is the best definition of a physical change?
A. Something that can be observed or measured while changing the identity of the substance.
B. A nail rusting.
C. A change that occurs without changing the identity of the substance.
D. Ice melting into water.
Answer:
the answer is D.ice melting into water
A student weighs out a 6.64 g sample of , transfers it to a 500. mL volumetric flask, adds enough water to dissolve it and then adds water to the 500. mL tick mark. What is the molarity of cobalt(II) fluoride in the resulting solution
Answer:
the molarity of cobalt(II) fluoride in the resulting solution is = 0.137 M
Explanation:
Given that :
a student dissolves 6.64 g of CoF₂ into 500 mL of water
volume of the solution(water) = 500 mL = 0.50 L
The standard molar mass of CoF₂ is 96.93 g/mol
number of moles of CoF₂ = mass of CoF₂/molar mass of CoF₂
number of moles of CoF₂ = 6.64 g/96.93 g/mol
number of moles of CoF₂ = 0.0685 mol
The molarity of any given substance is known to be as the number of moles of solute dissolved in one litre of solution.
Thus ;
Molarity of cobalt(II) fluoride CoF₂ in the resulting solution is = number of moles / Volume in (L)
Molarity of cobalt(II) fluoride CoF₂ = 0.0685 mol/ 0.50 L
= 0.137 M
Thus ; the molarity of cobalt(II) fluoride in the resulting solution is = 0.137 M
The initial temperature of a bomb calorimeter is 28.50°C. When a chemist carries out a reaction in this calorimeter, its temperature decreases to 27.45°C. If the calorimeter has a mass of 1.400 kg and a specific heat of 3.52 J/(gi°C), how much heat is absorbed by the reaction?
Answer:
D. 5,170 J
Explanation:
What is equilibrium?? Give examples
Answer:
it is when a state in which opposing forces or influences are balanced.
A example of equilibrium is in economics supply and demand are equal.
Explanation:
Answer:
Compromise of 1850
Explanation:
Consider an electrochemical cell based on the spontaneous reaction 2AgCl(s) + Zn(s) → 2Ag(s) + 2Cl– + Zn2+. If the zinc ion concentration is kept constant at 1 M, and the chlorine ion concentration is decreased from 1 M to 0.001 M, the cell voltage should:
Answer:
there is an increase by 0.18 V in the cell voltage.
Explanation:
The given equation of the reaction can be well written as
[tex]2AgCl_{(s)} + Zn _{(s)} \to 2Ag_{(s)} + 2 Cl^- _{(aq)}+ Zn^{2+}_{(aq)}[/tex]
By application of Nernst Equation ; we have the expression
[tex]E_{cell} = E^0- \dfrac{0,059}{n}log (\dfrac{[product]}{[reactant]})[/tex]
here in the above equation;
n = number of electrons transferred in the equation of the reaction
n = 2
Also;
[tex]E^0 = E_{cathode} - E_{anode}[/tex]
[tex]E^0 = E_{Ag^+/Ag} - E_{Zn^+/Zn}[/tex]
[tex]E^0 = +(0.80 \ V) - (-0..76 \ V)[/tex]
[tex]E^0 = (0.80 \ V +0..76 \ V)[/tex]
[tex]E^0 = 1.56 \ V[/tex]
If the zinc ion concentration is kept constant at 1 M; we have:
[tex]E_{cell} = E^0- \dfrac{0.059}{n}log (\dfrac{[product]}{[reactant]})[/tex]
[tex]E_{cell} = 1.56 - \dfrac{0.059}{2}log ({[Zn^{2+} ]}{[Cl^{2-}]})[/tex]
[tex]E_{cell} = 1.56 - \dfrac{0.059}{2}log (1)[/tex]
Since log(1) = 0
Therefore;
[tex]E_{cell} = 1.56\ V[/tex]
When the chlorine ion concentration is decreased from 1 M to 0.001 M; we have;
[tex]E_{cell} = E^0- \dfrac{0.059}{n}log (\dfrac{[product]}{[reactant]})[/tex]
[tex]E_{cell} = 1.56 - \dfrac{0.059}{2}log ({[Zn^{2+} ]}{[Cl^{2-}]})[/tex]
[tex]E_{cell} = 1.56 - \dfrac{0.059}{2}log ({[1*0.001^2}]})[/tex]
[tex]E_{cell} = 1.56 - 0.0295 \ * \ log ({[1*10^{-6}}]})[/tex]
[tex]E_{cell} = + 1.737 \ V[/tex]
The change in voltage = [tex]E_{cell} - E^0[/tex]
=( 1.737 - 1.56 )V
= 0.177 V
≅ 0.18 V
Thus; from the following observation; there is an increase by 0.18 V in the cell voltage.
The voltage of the cell increased by 0.18 V.
The equation of the reaction is; 2AgCl(s) + Zn(s) → 2Ag(s) + 2Cl– + Zn2+
We know that;
E°cell = 1.36 - (-0.76) = 2.12 V
If the cells are both at 1M concentration the Ecell = E°cell = 2.12 V
When the concentration of Cl- decreased from 1 M to 0.001 M
Ecell = E°cell - 0.0592/n log Q
Substituting values;
Ecell = 2.12 V - 0.0592/2 log (1 × (0.001)^2)
Ecell = 2.298 V
Increase in voltage = 2.298 V - 2.12 V = 0.18 V
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sodium chloride is called an electrovalent compound where as carbon dioxide is called covalent compound why
Electrovalent compounds are those that are created when one or more electrons are transferred from one atom to another inside the compound. NaCl is an electrovalent substance because it shares an electron with other compounds to produce them.
What are compounds ?A material created by chemically joining two or more distinct components. Examples of compounds are table salt (NaCl), which is generated from the elements sodium and chloride, and water (H2O), which is created from the components hydrogen and oxygen.
One carbon atom and two oxygen atoms combine to form carbon dioxide. One carbon dioxide molecule contains four covalent connections. Because neither carbon nor oxygen are metals, we can infer that carbon dioxide is a covalent molecule.
Pure substances known as compounds are created chemically when two or more elements are combined in a specific mass proportion. Chlorine and sodium combine to form sodium chloride (common salt).
Thus, sodium chloride is called an electrovalent compound whereas carbon dioxide is called covalent compound.
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