Answer:
Strontium is the elements which can be found in this group as it is shiny, is solid in room temperature and has atoms with two valence electrons.
b) The size of a star is a balance between
2 things. Explain this statement.
Answer:
Luminosity is the amount of light that a star radiates. The size of the star and its surface temperature determine its luminosity. Apparent magnitude of a star is its perceived brightness, factoring in size and distance, while absolute magnitude is its true brightness irrespective of its distance from earth
Explanation:
William adds two values , following the rules for using significant figures in computations. He should write the sum of these two number by using
Answer:
when it comes to adding or subtracting numbers, his final answer should have the same number of decimal places as the least precise value.
For example if you add 2 numbers; 10.443 + 3.5 , 10.443 has 3 decimal places and 3.5 has only one decimal place.
Therefore 3.5 is the less precise value.
So when adding these 2 values the final answer should have only one decimal place.
after adding we get 13.943 but it can have upto one decimal place. then the second decimal place is less than 5 so the answer should be rounded off to 13.9.
the answer is the same number of decimal places as the least precise value
Explanation:
I think this is the answer I'm not sure
Answer: the same number of decimal places as the least precise value
Explanation:
Please help me
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Explanation:
a) The presence of sulfate ions in a solution can be confirmed by the reaction of barium chloride in an acidic medium.
The balanced chemical equation of the reaction is shown below:
[tex]BaCl_2(aq)+CuSO_4(aq)->CuCl_2(aq)+BaSO_4(s)[/tex]
Hence, the white precipitate is barium sulfate and its formation with the ionic equation is shown below:
[tex]Ba^2^+(aq)+SO_4^2^-(aq)->BaSO_4(aq)[/tex]
b) The presence of copper (II) ions can be confirmed by the following test:
Add potassium iodide solution to copper (II) solution.
Then a white ppt of cuprous iodide along with the liberation of iodine is observed and the entire solution attains brown color.
The chemical equation of the reaction is shown below:
[tex]2CuSO_4(aq)+4KI(aq)->Cu_2I_2(s)+I_2(s)+2K_2SO_4(aq)\\[/tex]
c)(i)Due to this reaction, the blue color of the solution becomes white.
Reddish-brown copper is deposited at the bottom of the container.
(ii)In this reaction, zinc is oxidized.
d) (i) Copper is produced at the cathode.
(ii)[tex]Cu^2^+(aq)+2e^-->Cu(s)[/tex]
(iii) The reaction that takes place at the cathode is reduction.
Reduction is gaining of electrons.
The carbon atom forms a part of all the major molecules found in living things. Which of the following doesnot contain carbon?
Hydrochloric acid or Hcl
PLEASE HELPP!!!
PLEASE HELP!!!
Write the sentences in your copybook and draw a line through one of the words in
bold to complete each of these sentences about alkali metals correctly.
Alkali metals generally become more / less dense going down the group.
The melting and boiling points of alkali metals increase / decrease down the group.
The softness of alkali metals increases / decreases going down the group.
The speed with which alkali metals react with oxygen increases / decreases going
down the group.
Answer:
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Combustion reactions typically involve all of the following except
a. The consumption of oxygen gas
b. The production of a Hydrocarbon
c. The production of water
d. The release of carbon dioxide
Answer:
b. The production of a HydrocarbonExplanation:
In Combustion reaction usually occurs when a hydrocarbon reacts with oxygen to produce carbon dioxide and water.
Why does nuclear fusion occur in stars but not on Earth?
A.
There are no elements on Earth that can undergo fusion.
B.
Too many free neutrons are present on Earth.
C.
Fusion reactions require a lot of heat and pressure.
D.
Elements capable of undergoing fusion can’t be enriched on Earth.
Answer:
C. Fusion reactions require a lot of heat and pressure
Explanation:
A Nuclear fusion doesn't occur naturally on Earth because it requires temperatures far higher than Earth temperatures. Nuclear fusion takes place only at extremely high temperatures. That's because a great deal of energy is needed to overcome the force of repulsion between the positively charged nuclei.
What has an atomic number of 1
Answer:
Hydrogen
Explanation:
How does the position of an object relate to the energy stored in a object?
Answer:
An object can store energy as the result of its position. For example, the heavy ball of a demolition machine is storing energy when it is held at an elevated position. This stored energy of position is referred to as potential energy. Similarly, a drawn bow is able to store energy as the result of its position
Answer:
you can see the attached file is scanned the same level of detail of the heart the heart and I am a little bit of an emergency you can see it on the heart the tree is the best of luck for tomorrow be in a few days and times are available in a while back and forth to be a good idea and latitude longitude of
Number of sodium atom(s) in salt (NaCl)
Answer:
NaCl consists of one atom each of sodium and chlorine. Hence, each molecule of NaCl has 2 atoms total.
Explanation:
Answer: There is only one atom of sodium in NACL
Explanation: But in total there two atoms because 1 sodium and 1 chlorine added all together
HOPE THIS HELPS!!!!
if excess nitrogen gas reacts with 600 cm³ of hydrogen gas at room conditions , calculate the maximum volume of ammonia produced from the reaction? the chemical question is N2 + 3H2 = 2NH3
Answer:
400 cm³ of ammonia, NH₃.
Explanation:
The balanced equation for the reaction is given below:
N₂ + 3H₂ —> 2NH₃
From the balanced equation above,
3 cm³ of H₂ reacted to produce 2 cm³ of NH₃.
Finally, we shall determine the maximum volume of ammonia, NH₃ produced from the reaction. This can be obtained as illustrated below:
From the balanced equation above,
3 cm³ of H₂ reacted to produce 2 cm³ of NH₃.
Therefore, 600 cm³ of H₂ will react to produce = (600 × 2)/3 = 400 cm³ of NH₃.
Thus, 400 cm³ of ammonia, NH₃ were obtained from the reaction.
A gas that was heated to 150 Celsius has a new volume of 1587.4 L. What was its volume when its temperature was 100 Celsius?
Answer:
[tex]\boxed {\boxed {\sf 1058.3 \ L}}[/tex]
Explanation:
We are asked to find the new volume of a gas after a change in temperature. We will use Charles's Law, which states the volume of a gas is directly proportional to the temperature. The formula for this law is:
[tex]\frac {V_1}{T_1}= \frac{V_2}{T_2}[/tex]
The gas was heated to 150 degrees Celsius and had a volume of 1587.4 liters.
[tex]\frac {1587.4 \ L }{150 \textdegree C} = \frac {V_2}{T_2}[/tex]
The temperature was 100 degrees Celsius, but the volume is unknown.
[tex]\frac {1587.4 \ L }{150 \textdegree C} = \frac {V_2}{100 \textdegree C}[/tex]
We are solving for the volume at 100 degrees Celsius, so we must isolate the variable V₂. It is being divided by 100°C and the inverse of division is multiplication. Multiply both sides of the equation by 100°C.
[tex]100 \textdegree C *\frac {1587.4 \ L }{150 \textdegree C} = \frac {V_2}{100 \textdegree C} * 100 \textdegree C[/tex]
[tex]100 \textdegree C *\frac {1587.4 \ L }{150 \textdegree C} = V_2[/tex]
The units of degrees Celsius cancel.
[tex]100 *\frac {1587.4 \ L }{150 } = V_2[/tex]
[tex]100 *10.58266667 \ L = V_2[/tex]
[tex]1058.266667 \ L = V_2[/tex]
The original measurement of volume has 5 significant figures, so our answer must have the same. For the number we calculated, that is the tenth place. The 6 in the hundredth place to the right tells us to round to 2 up to a 3.
[tex]1058.3 \ L = V_2[/tex]
The volume of the gas at 100 degrees Celsius is approximately 1058.3 liters.
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even if u know how to do one, it's okk
anything helps
Explanation:
a) HNO2(aq) = HNO3(aq) + H2O(l) +NO(g)
b) SoCl2 (l) + H2O (l) = So2(g) + 2HCl(aq)
c) CH4 (g) + 2O2(g) = Co2 (g) + 2H2O(g)
d) 3CuO(s) + 2NH3 (g) = 3Cu(s) + 3H2O (l) + N2(g)
HELLO EVERYONE PLEASE I NEED HELP WITH
Please I REALLY NEED A HELP WITH THIS PLEASE HELP ME
THIS HARRY POTTER LITERARY ESSAY
OUTLINE
1. Love and Friendship is a central theme in Harry Potter and the Philosopher's Stone. Prove that this statement is true using 2(two) different characters from the novel as examples.
Introductory Statement/ Hook:
Statement of Intent: reason A and B :
thesis reason A and B:
BODY PARAGRAPH
#1 Point #1: Introduce REASON A here, but use general statement
#1: Provide quotations from the novel to support Reason A
Explanation #1:
Proof #2:
Explanation #2:
BODY PARAGRAPH
#2 Point #2: Introduce REASON B here, but use general statements
#1: Provide quotations from the novel to support ReasonB
Explanation #1:
Proof #2:
Explanation #2:
CONCLUSION
Restate/ Summarize Thesis:
Restate/ Summarize Points:
Answer:
Ron and Hermoine
Explanation:
They always fought over petty things, but at the end, they did end up together!
(Answer for your question about love and friendship being a central theme in Harry Potter and the Philosopher's stone)
*ALSO, MY ANSWER MIGHT BE WRONG* so be sure to use a pencil just in case!
I need help with question 5
Answer:
B a spring being stretched
How many moles are in 32g of O2?
Answer:
1 mol of O2
Explanation:
n = m/ M
n = 32/ ( 2× 15.999)
n= 1 mol of O2
How many grams of H2Oare produced when 5.38g of O2
is reacted?
Answer:
I think this answer should be 2.33 g H2O
Plants in forests take up carbon dioxide from the atmosphere during photosynthesis. They transform the carbon dioxide into plant material. When plants die, their organic matter is often worked into the soil by decomposers. Some of this organic matter remains within the soil and forest floor, and some of it is taken up by other living things.
Based on this information, what role do forests play in the carbon cycle?
A.
Forests are carbon sinks because they store carbon.
B.
Forests are carbon sinks because they do not absorb carbon dioxide when plants die.
C.
Forests are carbon sources because they emit carbon.
D.
Forests are carbon sources because they can be burned to emit carbon dioxide.
Answer: B. forests are carbon sinks because they store carbon
Explanation:forests take up carbon from the atmosphere through photosynthesis and from organic matter through decomposition. so, forests are carbon sinks because they store carbon
There is a series of nitrogen oxides with the general formula N?O?. What is the empirical formula of one that contains 30.45% nitrogen?
Question 13 options:
N2O
NO
NO2
N2O3
N2O5
Answer: The empirical formula of one that contains 30.45% nitrogen is [tex]NO_{2}[/tex].
Explanation:
Given: Mass of nitrogen = 30.45 g
Let us assume that the mass of given oxide is 100 grams.
As the atomic mass of nitrogen is 14.0067 g. So, moles of nitrogen will be calculated as follows.
[tex]Moles = \frac{mass}{molarmass}\\= \frac{30.45 g}{14.0067 g/mol}\\= 2.17 mol[/tex]
Also, mass of oxygen = (100 - 30.45) g = 69.55 g
Atomic mass of oxygen is 15.9994 g/mol. So, moles of oxygen will be as follows.
[tex]Moles = \frac{mass}{molarmass}\\= \frac{69.55 g}{15.9994 g/mol}\\= 4.34 mol[/tex]
The ratio of both the atoms is as follows.
[tex]\frac{4.34}{2.17} = 2[/tex]
This means that gas has 2 moles of oxygen to 1 mole of nitrogen. Hence, the formula of oxide is [tex]NO_{2}[/tex].
Thus, we can conclude that the empirical formula of one that contains 30.45% nitrogen is [tex]NO_{2}[/tex].
Which statement includes all the steps in the change that is associated with the enthalpy of solution? solute separation and mixing reaction of reactants to form products. solute and solvent mixing and then separating solute separation, solvent separation, and then mixing
Answer: solute separation, solvent separation, and then mixing
Explanation:
The enthalpy change of solution simply means the amount of heat which can be released or absorbed when dissolving. The enthalpy of solution is usually expressed at constant temperature in kJ/mol.
The enthalpy of solution requires three main stages:
1. Solute separation: This is when the solute is broken down. In this case, all the intramolecular forces which holds the solute together is broken.
2. Solvent separation: This is when the solvent is broken down all the intramolecular forces which holds the solvent together is broken.
3. Mixing- In this case, the solute and the solvent is mixed for a solution.
What is nascent hydrogen?
Answer:
[H]
Explanation:
This is nascent hydrogen it's a reactive form of hydrogen...
It reduces elements and compounds.
Need help fast!!
What is the pH of a solution with a 1.50 x 10-9 M hydroxide ion concentration? (4
points)
1) 0.176
2) 5.18
3) 8.82
4) 9.20
Answer:
The answer is "5.18 ".
Explanation:
It's a question of chemistry. Therefore, the following solution is provided:
We will first determine the solution's pOH. The following can possible:
The concentration of Hydroxide ion [tex][OH^{-}] = 1.5\times 10^{-9}\ M[/tex]
[tex]pOH =?\\\\pOH = -\log [OH^{-}]\\\\pOH = -\log 1.5\times 10^{-9}\\\\pOH = 8.82\\\\[/tex]
Furthermore, the pH of the solution shall be established. It was provided as follows:
[tex]pOH = 8.82\\\\pH =?\\\\pH + pOH = 14\\\\pH + 8.82 = 14\\\\[/tex]
When collecting all the like terms:
[tex]pH = 14 -8.82\\\\pH = 5.18[/tex]
Therefore, the solution of pH is 5.18.
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Answer:
64g of [tex]\bold{CH_{3}OH}\dashrightarrow[/tex]44.8L
vapour density of [tex]CH_{3}3OH=\frac{mass}{volume}[/tex] of [tex]\bold{CH_{3}OH}[/tex]
=64/44.8=10/7=1.43 g/l
Vapour density of [tex]\bold{CH_{3}OH}[/tex]=1.43g/l
64g of [tex]\bold{CH_{3}OH => 44.8L }[/tex]
vapour density of [tex]\small{\sf{CH_{3}3OH=\frac{mass}{volume} of } \bold{CH_{3}OH}}[/tex]
=64/44.8=10/7=1.43 g/l
Vapour density of [tex]\bold{CH_{3}OH = 1.43 g/L}[/tex]
What is the reducing agent in the reaction Fe + AgNO3 → Fe(NO3)3 + Ag?
O A. Fe
B. AgNO3
C. Fe(NO3)3
D. Ag
Answer:
A.
Iron, Fe
explanation:
Iron reduces silver nitrate to silver.
Answer:
agno3
Explanation:
just took the quiz
Plz Help I have One more time To retake and I can't fail it..
Answer:
D
Explanation:
A synthesis reaction is a reaction in which two or more reactants combine to form a given product.
If we look closely at option D, you will notice that sulphur and oxygen combined together to form sulphur dioxide. That is a typical example of chemical synthesis.
Hence;
S + O2 ----->SO2 is a synthesis reaction.
what is the charge on ion X Li2X
In the compound Li2X, there are two lithium ions and one X^2- ion.
Ionic compounds are composed of an ion pair of opposite charge. Usually, the positive ion is a metal cation while the negative ion is a non metal anion. The two ions are held together by strong electrostatic interaction.
In the compound Li2X, there are two lithium ions and one X^2- ions. X^2 -is the non metal anion present.
Learn more: https://brainly.com/question/2673886
How many moles of KOH are there in 27.5 mL of 0.250 M KOH?
Question 2 options:
4.31 × 10−3 mol KOH
6.88 × 10−3 mol KOH
7.24 × 10−3 mol KOH
8.13 × 10−3 mol KOH
9.21 × 10−3 mol KOH
Answer:
6.88 × 10^-3mol
Explanation:
Molarity = number of moles (n) ÷ volume (V)
According to this question, there in 27.5 mL of 0.250 M KOH, the number of moles of KOH can, therefore, be calculated as follows:
number of moles = molarity × volume
Volume of KOH = 27.5mL = 27.5/1000
= 0.0275L
n = 0.0275 × 0.250
n = 0.006875 mol
n = 6.88 × 10^-3mol
what is the difference between double salt and complex salt
Answer:
The main different of double salt and complex salt is that a double salt is a combination of two salt compounds whereas a complex salt is a molecular structure that is composed of one or more complex ions.
MULTIPLE CHOICE QUESTION
Substances that would be described as an Element (such as Argon gas Ar,
fluorine gas F2, pure metal like gold Au ) have an oxidation state of what
number?
mentary
2
3
-1
1
O
Answer:
the oxidation number of those elements is 2 because some of them are molecules
A pupil has drawn the electronic structure of fluorine and the diagram is shown below. However,
mistakes have been made. State three mistakes that have been made.
Fl atomic number: 9
Fl atomic mass: 10
(ps i have two of these but can’t figure out the last)
Answer:
The number of electrons in the orbit is wrong they have to be 9 and not 10since flourine is in group 7 the number of electrons in the outer most shell has to be 7 and not 2the first shell has 8 instead of 2 electronsI hope this helps
