Answer:
To find the number of neutrons in an isotope, subtract the number of protons from the atomic mass of the isotope. The atomic number of the element equals the number of protons.
Help! please i'm kinda stuck in here and i know it's really easy but i literally forgot
Alpha particle radiation will most likely result when
electrons gain energy.
atoms become charged.
two atoms are near one another.
the nucleus becomes unstable.
Answer:
electrons gain energy
Explanation:
A sample of a substance who only oxidizable material is tin in the +2 state, is titrated with a dichromate solution that was prepared by dissolving 1.226g of K₂Cr₂O₇ in enough water to give a volume of 250.00cm³. A 0.0821g sample of the substance required a volume of 23.90cm³ of the titrant to reach the equivalence point . The product of the oxidation of the tin in the +2 state is to tin in the +4 state . The reduction product of the dichromate , is chromium in the +3 state. Calculate the % of tin in the substance . ( NB: Assume the reaction to take place in acidic )
Given that, the sample of a substance who only oxidizable material is tin in the +2 state and we are meant to the determine the percentage composition of tin in the substance;
Then, the percentage composition of the tin in the substance is calculated as 172.84%
From the given information:
The molecular weight is the addition of all the atomic masses of a compound.
The molecular weight of K₂Cr₂O₇ is calculated as follows:
= (2 × 39.1) + (2 × 52) + (7 × 16)
= 294.2
The molecular weight of Sn²⁺ = 118.7
The oxidation half-reaction for Tin(ii) ion is as follows:
[tex]\mathbf{Sn^{2+}\to Sn^{4+}+2e^{-}}[/tex]
From the above equation, Tin (ii) ion oxidizes to Tin (iV) ion
The reduction of K₂Cr₂O₇ In the acidic medium, reduce Cr₂ to Chromium Cr³⁺.
[tex]\mathbf{K_2 Cr_2O_7 + 14H^{+}+6e^- \to 2K^+ + 2r^{3+} + 7H_2O}[/tex]
To calculate the percentage % of Tin in the sample, we must first know the Equivalent weight of each substance.
Calculating the equivalent weight (Eq. weight) of each substance in the samples, we have the following:
For K₂Cr₂O₇:
[tex]\mathbf{Eq. weight = \dfrac{molecular \ weight }{numbers \ of \ electrons \ lost \ or \ gained }}[/tex]
[tex]\mathbf{Eq. weight \ of \ K_2Cr_2O_7 = \dfrac{294.2 }{6}}[/tex]
[tex]\mathbf{Eq. weight \ of \ K_2Cr_2O_7 = 49.03 \ g/eq}[/tex]
[tex]\mathbf{Eq. weight \ of \ Sn^{2+} = \dfrac{118.7 }{2}}[/tex]
[tex]\mathbf{Eq. weight \ of \ Sn^{2+} =59.35 g/eq}[/tex]
The next step is to determine the Normality of the Solution.
Normality refers to the mole number per liter of the solution
[tex]\mathbf{Normality \ of \ K_2Cr_2O_7 = \dfrac{1.226 \ g }{49.03}\times \dfrac{1000}{250}}[/tex]
[tex]\mathbf{= \dfrac{4.904}{49.03} N}[/tex]
So, 23.90 mL of [tex]\mathbf{ \dfrac{4.904}{49.03} N}[/tex] of K₂Cr₂O₇ is required to be present in the solution.
= [tex]\mathbf{=23.90 mL \times \dfrac{4.904}{49.03 } \ of \ Sn \ ion}[/tex]
Thus, the amount of Sn in the sample is calculated as:
[tex]= \mathbf{\dfrac{4.904}{49.03}\times \dfrac{59.35}{1000}\times 23.90 \ mL}[/tex]
= 0.1419 g
Finally, the percentage composition of tIn (Sn) in the sample is:
[tex]\mathbf{= \dfrac{0.1419}{0.0821}\times 100\%}[/tex]
= 172.84%
NOTE: A 0.0821g sample of the substance was given. Ideally, it should be 0.821g. But the calculation was based on the data given.
Therefore, from the above explanation, we can conclude that the percentage % of Sn in the sample is 172.84%
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In the laboratory, open-toed shoes and shorts:
a. Are potentially dangerous and should not be worn.
b. Are OK if the weather is hot.
c. Are all right if you are wearing a lab coat
d. Are OK if they are in style.
Answer:
a. Are potentially dangerous and should not be worn.
why does magnesium donate two electrons to oxygen in order to form magnesium oxide (MgO)?
Answer:
electron arrangement of Mg is 2.8.2. To reach a stable octet electron arrangement Mg donates 2 electron to oxygen.Hence, Mgo ion formed.
tetrachloromethane and water can be seperated using a seperating funnel . what can be reduced from this statement
Answer: Hello There!................
Separating funnuel. AND
Explanation:
Carbon tetrachloride and water are separated by using a separating funnel. Carbon tetrachloride and water are imiscible with each other. Hence, they form two layers. The density of carbon tetrachloride is more dense than water and forms lower layer. Water being less dense, forms upper layer.
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Consider a cloudless day on which the sun shines down across the United States. If 2559 kJ of energy reaches a square meter (m2) of the United States in one hour, how much total solar energy reaches the entire United States per hour? The entire area of the United States is 9,158,960 km2 .
In 1 hour, 2.344 × 10¹⁶ kJ of solar energy reaches the United States.
The entire area of the United States is 9,158,960 km². We will convert it to m² using the conversion factor 1 km = 10³ m, squared.
[tex]9,158,960 km^{2} \times (\frac{10^{3} m }{1km} )^{2} = 9.158960 \times 10^{12}\ m^{2}[/tex]
In order to find the amount of solar energy that reaches 9.158960 × 10¹² m² we will use another conversion factor: 2559 kJ of energy reaches a square meter of the United States in one hour.
[tex]9.158960 \times 10^{12}\ m^{2} \times \frac{2559 kJ}{m^{2}.h } = 2.344 \times 10^{16} kJ/h[/tex]
In 1 hour, 2.344 × 10¹⁶ kJ of solar energy reaches the United States.
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Outline the main sources of industrial material
Answer:
In chemistry, an element is a pure substance consisting only of atoms that all have the same numbers of protons in their atomic nuclei. Unlike chemical compounds, chemical elements cannot be broken down into simpler substances by chemical means. Wikipedia
What does the half-life of a radioactive substance indicate?
A. It indicates how dangerous the substance is to humans.
B. It indicates how much energy is released over time.
C. It indicates how long it takes for the material to decay.
D. It indicates how long it takes until all radioactivity is gone
Answer:
it indicates how long it takes for the material to decay
Explanation:
hope this helps!
The half-life of a radioactive substance indicates how long it takes for the material to decay.
What is half-life of a radioactive?A half life is the amount of time it takes for half of a radioactive substance to decay.
Radioactive isotopes are defined as the isotopes which undergo decay processes very easily. They have very short half life. They are usually the isotopes of heavier elements.
Half life is defined as the time taken for the unstable isotope to fall to half its original value.
Hence, option C is correct.
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List the steps of the scientific method
Easy points, just don't be annoying.
Answer:
•1. Make an Observation
•2. Ask a question about ____
•3. Make a hypothesis (educated guess)
•4. Make a hypothesis-based prediction
•5. Test your hypothesis
•6. Graph the results and Iterate.
Answer:
The steps of the scientific method are:-
●Report the Results.
●Ask a Question.
●Test the prediction.
●Make an observation.
●Form a hypothesis, or testable explanation.
●Make a prediction based on the hypothesis.
Tipo completacion. Está formado por un ion metálico y el grupo oh
Answer: Type complete. It is made up of a metal ion and the group oh
Gold can be hammered into decorative gold leaf, which is only 1.00E-07m thick. If 1.35 troy ounce of gold is hammered into gold leaf, what is the area that can be covered when used for decoration? 1 troy ounce = 31.1g, and the density of gold is 19.3 g/cm^3
The area that can be covered when used for decoration is 21.8 m².
To solve this question, we'll by converting 1.35 troy ounce to grams (g). This can be obtained as as illustrated below:
1 troy ounce = 31.1g
Therefore,
1.35 troy ounce = 1.35 x 31.1
1.35 troy ounce = 41.985 gThus, 1.35 troy ounce is equivalent to 41.985 g.
Next, we shall determine the volume of the gold leaf. This can be obtained as follow:
Mass = 41.985 g.
Density = 19.3 g/cm³
Volume =?[tex]Density = \frac{mass}{volume } \\\\19.3 = \frac{41.985}{Volume }[/tex]
Cross multiply
19.3 × Volume = 41.985
Divide both side by 19.3
[tex]Volume = \frac{41.985}{19.3}[/tex]Volume = 2.18 cm³Next, we shall convert 2.18 cm³ to m³.
1 cm³ = 1×10¯⁶ m³
Therefore,
2.18 cm³ = 2.18 × 1×10¯⁶ m³
2.18 cm³ = 2.18×10¯⁶ m³Thus, 2.18 cm³ is equivalent to 2.18×10¯⁶ m³.
Finally, we shall determine the area. This can be obtained as follow:
Volume = 2.18×10¯⁶ m³
Thickness = 1×10¯⁷ m
Area =?
Volume = Area × Thickness
2.18×10¯⁶ = Area × 1×10¯⁷
Divide both side by 1×10¯⁷
[tex]Area = \frac{2.18*10^{-6} }{1*10^{-7} }\\\\[/tex]Area = 21.8 m²Therefore, the area that can be covered when used for decoration is 21.8 m²
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On average an adults lung volume is 5 L convert to mL
[tex]\\ \sf\longmapsto 5L[/tex]
[tex]\\ \sf\longmapsto 5(1000)[/tex]
[tex]\\ \sf\longmapsto 5000mL[/tex]
formation of curd from milk is a chemical change
Answer:
yeah it's a chemical change because..Curd or Dahi is a fermented milk product formed by fermentation of milk by Lactic Acid bacteria to Lactic acid. Milk consists of globular proteins called casein. The curd forms because of the chemical reaction between the lactic acid bacteria and casein. ... The byproduct of ATP production is lactic acid.hope it helps..stay safe healthy and happy..Select the arrangement that orders the compounds by increasing boiling point based on predominant intermolecular force. Please choose the correct answer from the following choices, and then select the submit answer button. Answer choices N2 < CO2 < NH3 < HF
The arrangement that orders the compounds by increasing boiling point based on predominant intermolecular force is; N2 < CO2 < NH3 < HF
The molecules that compose a substance are held together by intermolecular forces. The physical properties of a substance such as boiling points depends on the nature of intermolecular forces between substances. The greater the magnitude of intermolecular interaction between bonding atoms the higher the boiling point.
Nitrogen and CO2 molecules are only held together by weak dispersion forces. However, CO2 has a higher boiling point than N2 because CO2 has a higher molecular mass than N2.
Nitrogen is less electronegative than fluorine hence the magnitude intermolecular interaction via hydrogen bonding in HF is greater than that in NH3 consequently, the boiling point of HF is higher than that of NH3.
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9.Out of the following which is a poly atomic molecule. (H2, CI 2.03.)
the poly atomic molecule is H2
Which Rocky planet's Biosphere is most different from Earth
Answer:
i guess it a right answer for you ✌
Mercury and venus are the two rocky planets that have the atmosphere most, unlike the Earth.
What are rocky planets?The planets Mercury, Venus, Earth, and Mars, are called terrestrial planets or rocky planets. This is because they have a compact, rocky surface like the Earth's. It's called terra firma.
The terrestrial planets are the four innermost planets in the solar system. These are also called inner planets. The terrestrial planets do not have rings. Earth has belts of trapped radiation.
Among the terrestrial planets, only Earth has a planetary magnetic field that is substantiated. The moons of Mars and the Earth have regional magnetic fields that are localized at various places around their surfaces but they have no global field.
Out of the terrestrial planets, only Venus, Earth, and Mars have significant atmospheres. The atmosphere of mercury is more or less like a vacuum. The gases that are present in a planetary atmosphere are related to the size, mass, temperature, of a planet and the formation of the planet, and about the presence of life.
Therefore, mercury and venus are the two rocky planets that have the atmosphere most, unlike the Earth.
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It's okay to have more than one independent variable in an experiment.
O True
O False
Answer:
False
Explanation:
I don’t know but I think it’s kinetic?
Answer:
heat
kinetic
sound
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Calculate the volume of CO₂ at NTP occupied by 44.4 gram of heat
We know at NTP each gas has 22.4L of volume .
[tex]\boxed{\sf 1mol\:of\:CO_2=22.4L=44g}[/tex]
Hence 1g of CO2 contain
[tex]\\ \sf\longmapsto \dfrac{22.4}{44}[/tex]
[tex]\\ \sf\longmapsto 0.5L[/tex]
Now 44.4g of CO_2 has
[tex]\\ \sf\longmapsto 0.5\times 44.4=22.2L[/tex]
1. Distinguish between a mixture and a pure substance.
Answer:
1)Mixture is the combination of substance
2)There are two types of mixture such as heterogeneous mixture and homogeneous mixture
3)foreg=Salt solution ,sedimentation
Pure substance
1)Pure substances are also called elements
2)They are made up of small atoms
3)for eg= oxygen,Venadium ,Iron,Oxygen
8. Predict the missing products of the double replacement reaction: MgCl2 + Na2S—___+____
a. MgS + NaCl2
b. MgS + NaCl
c. MgNa + CIS
d. MgNa2 + Cl2S
Answer:
d.MgNa2+Cl2S
Explanation:
the reaction should balance on both sides
How do you write a balanced chemical equation for the reaction of sulfuric acid with magnesium nitrate to form magnesium sulfate and nitric acid
a rabbit has a mass of 2 kg. what is the weight?
Is baking soda a element, compound or a mixture?
Answer:
Baking soda (sodium bicarbonate) is scientifically is a compound. It consists of different types of atoms (Sodium, Hydrogen, Carbon, and Oxygen) which chemically combine.
what is E1 reaction
Answer:
An elimination reaction is a type of organic reaction in which two substituents are removed from a molecule in either a one- or two-step mechanism. The one-step mechanism is known as the E2 reaction, and the two-step mechanism is known as the E1 reaction0
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Please answer all questions as completely as possible showing all work needed. Also don’t forget to include your units
density = mass / volume
d = m / V
2) Calculate the density of a material that has a mass of 52.457 g and a volume of 13.5 cm3.
3) A student finds a rock on the way to school. In the laboratory he determines that the volume of the rock is 22.7 mL, and the mass in 39.943 g. What is the density of the rock?
4) The density of silver is 10.49 g/cm3. If a sample of pure silver has a volume of 12.993 cm3, what is the mass?
5) What is the mass of a 350 cm3 sample of pure silicon with a density of 2.336 g/cm3?
6) Pure gold has a density of 19.32 g/cm3. What volume would a piece of gold have if it has a mass of 318.97 g?
7) The density of lead is 11.342 g/mL. What would be the volume of a 200.0 g sample of this metal?
8) The mass of a toy spoon is 7.5 grams, and its volume is 3.2 mL. What is the density of the toy spoon?
9) A 28.5 g of iron shot is added to a graduated cylinder containing 45.50 mL of water. The water level rises to the 49.10 mL mark, from this information, calculate the density of iron.
10) A rectangular block of copper metal weighs 1896 g. The dimensions of the block are 8.4 cm by 5.5 cm by 4.6 cm. From this data, what is the density of copper? (Hint: V = l x w x h)
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Please check if that’s right
Answer:
Explanation:
yes
Please help me please
Explanation:
1 sugar solution =Distillation
2 Iron powder and sand=magnetic separation
3 petrol and diesel= Fractional distillation
4 Camphor and glass powder = Sublimation
Someone answer this please
To convert something in kilojoules to joules, you need to:
Multiply by 1,000
1
Divide by 1,000
2
Multiply by 1,000,000 3
Divide by 1,000,000
4
Answer:
Divide by 1000
Explanation:
Have a good day
Hope I helped
Multiply by 1000 .
I HOPE IT WILL HELP YOU.
HOPE your day goes great.
