Answer:
1s2, 2s1
Explanation:
Lithium is the first element in the 2nd row of elements meaning its 1s orbital is completely filled and 1 electron is in the 2s orbital.
Answer:
the answer is C
Explanation:
It id desired to increase thr volume of gas by 20% without changing the pressure .To what temperature the gas must be heated if the initial temperature of the gas is 27degree celcius?
Answer:
32.4°C
Explanation:
Consider the following expression:
P•V/T =P'•V'/T'
Where P and P' are respectively the initial and the final pressure, V and V's are respectively initial and final volume, and T and T' are respectively initial and final temperature.
We know that the pressure cannot change, so it means that P = P'
We also know that the volume must be increased in 20%, and if we multiply the volume by 1.2 is like increase it in 20%, so we can write that V' = 1.2•V, and changing a little more we can write that V'/V = 1.2
So let's do some maths:
P•V/T = P'•V'/T'
T'•P•V/T = P'•V'
T'•P•V = P'•V'•T
T'=P'•V'•T/P•V
We know that P'=P so the division is equal to 1:
T'= 1•V'•T/V
We also know that V'/V = 1.2, so:
T' = 1.2•T
And we know the value of T, it's 27, so now we just have to solve it:
T' = 1.2•27
T' = 32.4°C
if any 1 studying 11th can u plz send me the chemistry notes for chapter 2 STRUCTURE OF AN ATOM lesson
plz send me honestly cause i have exam day after tommorow .so plz send unwanted answer
I BEG U
Answer:
What
You cant just send notes you also have to say where you are and which book you are using because others are different
(b)
Huiting wanted to find out the hardness of two materials H and F. She used a
rounded object made of material G and forced it into each material with the
same force. The results of her experiment are shown below.
rounded object of
material G
rounded object
of material G
3 mm
1 mm
object of
material H
object of
material F
List materials F, G, H in increasing order of hardness. Explain your answer.
[2]
Object named H is harder than Object F due to its thickness.
The object of material H is harder than the object of material F due to the difference in thickness. The thickness of Material Object H is 3 millimeters compared to Material Object F which is 1 millimeter thick, so applying the same amount of force on both objects, Material Object H does not show any change in its structure while on the other hand, the shape of the object F changes due to a lower hardness.
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are standard electrode potential and standard hydrogen potential same?
Answer:
Potentials of any other electrodes are compared with that of the standard hydrogen electrode at the same temperature. Hydrogen electrode is based on the redox half cell: 2 H+(aq) + 2 e− → H2(g)..
A mineral sample has a mass of 35 g. When it is dropped into a graduated cylinder with 25mL of water, the volume of the water rises to 35 mL. Using this data, determine the density of the sample.
Answer:
3.5g/ml
Explanation:
density=mass/volume
the mass of the mineral we have been given to be 35g
and it's volume is found by subtracting the initial volume from the final volume which is 35ml-25ml=10ml
Answer:
[tex]\boxed {\boxed {\sf 3.5 \ g/mL}}[/tex]
Explanation:
The density of an object is the mass per unit volume, so the formula is:
[tex]\rho= \frac {m}{v}[/tex]
We know the mass of the mineral sample is 35 grams.
We have to calculate the volume. The volume was found using water displacement. An amount of water was put in a graduated cylinder, then the object was dropped in. The volume is the difference between the final water level and the initial water level.
v= final water - initial water v= 35 mL - 25 mL v= 10 mLNow we know the mass and volume of the mineral sample.
m= 35 g v= 10 mLSubstitute the values into the formula.
[tex]\rho= \frac{35 \ g}{10 \ mL}[/tex]
Divide.
[tex]\rho = 3.5 \ g/mL[/tex]
The density of the mineral sample is 3.5 grams per milliliter.
Which of the following would be most likely to form a +2 cation?
The Periodic Table
A. Sulfur (S)
B. Calcium (Ca)
C. Chlorine (CI)
O D. Potassium (K)
Calcium because group 2 metals are all 2+ cations
Which atom would be neutral?
1an oxygen atom with 16 electrons, 18 protons, and 16 neutrons
2an oxygen atom with 4 electrons, 6 protons, and 4 neutrons
3an oxygen atom with 9 electrons, 8 protons, and 8 neutron
4an oxygen atom with 8 electrons, 8 protons, and 9 neutrons
Answer:
an oxygen atom with 8 electrons, 8 protons, and 9 neutrons
Explanation:
A proton has a positive charge and an electron has a negative charge. Magnitude of both of these charges is same. So, we need the same number of electrons and protons to make the atom neutral.
Neutron is neutral, so we can safely ignore it in this question.
Answer:
an oxygen atom with 8 electrons, 8 protons, and 9 neutrons
Explanation:
Can someone plz help me :<
Answer: cats r alliens because they r kind of like ufos they would usually wonder around rather u know it or not when they spy on us it could b with us sleep cooking anything so they r like aliens
Explanation:
Determine the grams of sodium chloride produced when 10 g of sodium react with 10 grams chlorine gas according to the equation 2Na + Cl2 = 2 NaCl
Answer:
16 g
Explanation:
Step 1: Write the balanced equation
2 Na + Cl₂ ⇒ 2 NaCl
Step 2: Identify the limiting reactant
The theoretical mass ratio (TMR) of Na to Cl₂ is 46:71 = 0.65:1.
The experimental mass ratio (EMR) of Na to Cl₂ is 10:10 = 1:1.
Since EMR > TMR, Cl₂ is the limiting reactant
Step 3: Calculate the mass of NaCl produced
The theoretical mass ratio of Cl₂ to NaCl is 71:117.
10 g Cl₂ × 117 g NaCl/71 g Cl₂ = 16 g NaCl
How much does 9.8 liters of ammonia (NH3) weigh at standard temperature and pressure (273 K and 100 kPa)?
A. 13.84 grams
B. 7.44 grams
C. 17 grams
D. 12.91 grams
Reset Selection
What is the volume of 3.6g of material with a density of 13.2g/mL? Include units and go to 4 decimal places.
Answer:
0.2727 mL
Explanation:
use density to convert mass to volume
3.6 g x 1 mL = 0.2727 mL
13.2 g
Which of the following represents an endothermic reaction?
Select one:
a. S(s) +O2(g) → SO2(g) ΔH = -297kJ
b. 2NO2(g) → N2(g) + 2O2(g) + 33.8kJ
c. N2(g) + 2O2(g) + 90.4kJ → 2NO2
d. N2H4(g) + O2(g) → N2(g) +2H20(g) + 627.6 kJ
B because decomposition reactions are often caused by the application of heat to break up the bonds within the molecules, which will form the molecules that made up the decomposed molecule.
1s 2s22p63s23p4
How many valence electrons does this atom have?
2
6
4
12
Answer:
6
Explanation:
How many valence electrons does this atom have?
answer 6
Answer:
6.
Sulphur has 6 valence electrons.
( .°. that's the electronic configuration of sulphur .)
How does a scientific theory differ from a guess or an opinion?
Answer:
Scientific theory differs from a guess or opinion because a scientific theory is a system of ideas that explains many related observation and is supported by a large body of evidence acquired through scientific investigation while guesses and opinions may not reliably predict an outcome, have evidence to back up the theory
Explanation:
A scientific theory is defined as the explanation of the universe and the natural sciences. It differs from opinions and guesses as they are supported by observations and evidence.
What is a scientific theory?A scientific theory has been a detailed description and explanation of the natural sciences and the universe that are studied and developed with the help of the hypothesis and the facts.
It relies on the scientific method to conclude the accountability by observing, estimating, and then concluding the matter with supportive evidence.
It differs from guess and opinions as it involves investigations, research, evidence to back the idea, whereas the latter and are not reliable and lacks evidence.
Therefore, scientific theory differs from opinion.
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write the balanced chemical equation for the following word equation. sodium+sulphate Acidsodium sulphate +hydrogen
Answer:
2NaOH+ H2SO4 → Na2SO4 + 2H2O
I HOPE ITS RIGHT IF NOT THEN SORRYHAVE A GREAT DAY :)
Answer:
Sodium+sulphate=Na2SO4
Acidsodium sulphate + hydrogen=Na2SO4+H2O
Write a hypothesis that answers the lesson
question, "While observing a chemical reaction,
how can you tell which reactant is limiting?"
Hypothesis: If a substance is the limiting
reactant, then..
Answer:
the reaction will come to a halt and the other reactant will still be present.
Write an equation to show how perchloric acid, HClO4, reacts with water. Include states of matter in your answer.
Since perchloric acid is a strong acid, it will dissociate completely, along with water. The products will be Perchlorate ions and Hydronium ions after the Perchloric acid gave away its proton and water, acting as a base, accepted that abandoned proton.
write an importance of endothermic reactions
Answer:
the uses of exothermic reactions are:
1) lighting of stove
2) self heating cans
3) hand warmers
4) in some case exothermic process can be used to cook food such as rice (by adding calcium oxide to water heat is evolved and it helps to cook food )
Explanation:
hope this helps you pls mark me as brainilst
Which metal can replace another metal in a reaction?
A. Any metal on the list can replace any other metal also on the list.
B. A metal on the activity series list will replace one that is not on the
list.
C. A metal lower on the activity series list will replace one that is
higher
D. A metal higher on the activity series list will replace one that is
Tower
Answer:
D
Explanation:
The atoms of the more reactive metal push their electrons on to ions of the less reactive metal.
Which sentence describes existing cells?
All cells, once formed, continue to live forever.
All cells come from previously existing cells.
All the cells that are on Earth have always been here.
All cells develop from the remains of other cells.
Describe the formation of oxygen molecule
Answer:
oxygen molecule has two oxygen atom . Each O atom share 2 electrons to form two covalent bonds out of which one is sigma bond and other is pi bond . sigma bond is formed by axial overlap 2p atomic orbitals of oxygen and pi bond is formed of lateral overlap of 2p atomic orbitals of oxygen .
How does the chemistry of the ocean change in response to high levels of CO2 in the atmosphere?
what is element Na in a periodic table
Answer:
Sodium.
Explanation:
Sodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table. Its only stable isotope is ²³Na.
Answer:
sodium
atomic mass 22.99
atomic number 11
period 3 group 1 1a
sodium is also an Alkali metal
Explanation:
I have a periodic table on my computer I hope I helped
can you solve this.
I need it.
:) :):)
Answer:
12
45
ahagosmssjajjapaps3
PLS HELP!! WILL MARK BRAINLIEST! 99 POINTS!
You're going to first balance the chemical equation.
After that, convert the grams of Na into moles of Na, and then multiply that with the ratio of moles of NaCl to Na, and then convert the mol of NaCl into grams in order to obtain the theoretical yield, since we are given that Na is the limiting reactant.
After that, plug the values into the yield formula, doing some basic algebra, and you should get your result.
You're going to first balance the chemical equation.
After that, convert the grams of Na into moles of Na, and then multiply that with the ratio of moles of NaCl to Na, and then convert the mol of NaCl into grams in order to obtain the theoretical yield, since we are given that Na is the limiting reactant.
After that, plug the values into the yield formula, doing some basic algebra, and you should get your result.
Our burning of fossil fuels for energy poses several different problems. Describe what is generally considered the biggest problem and the main reason for using alternatives.
PLEASE HELP!!
Which medicines are including Chemicals?
Can you help Please!
Answer:
Compounds used as medicines are most often organic compounds, which are often divided into the broad classes of small organic molecules (e.g., atorvastatin, fluticasone, clopidogrel) and "biologics" (infliximab, erythropoietin, insulin glargine), the latter of which are most often medicinal preparations of proteins
what is cytoplasm ? what does it contain?
Answer:
Cytoplasm is a thick solution that fills each cell and is enclosed by the cell membrane. It is mainly composed of water, salts, and proteins. All of the organelles in eukaryotic cells, such as the nucleus, endoplasmic reticulum, and mitochondria, are located in the cytoplasm.
Answer:
Explanation:
Cytoplasm is a thick solution that fills each cell and is enclosed by the cell membrane. It is mainly composed of water, salts, and proteins. All of the organelles in eukaryotic cells, such as the nucleus, endoplasmic reticulum, and mitochondria, are located in the cytoplasm. ...
3. An atom
OF
elemente A has mass number 39 and 19 protons
Write the electron arrangement of the atom
Answer:
Explanation:
Potassium (K) atom has 19 electrons. The full electron configuration of Potassium (K) is 1s22s22p63s23p64s1
Principal energy level
Quantum number: n
1
2
3
4
5
6
Sublevels
availableQuantum number: l
1s
2s 2p
3s 3p 3d
4s 4p 4d 4f
5s 5p 5d 5f 5g
6s 6p 6d 6f 6g 6h
A reaction happens quickest during:
A. The beginning of the reaction
B. It is constant throughout the reaction
C. The end of the reaction
D. The middle of the reaction
The reaction is the formation of the product from the reactants. A reaction happens quickest during the beginning of the reaction. Thus, option A is correct.
What are the factors affecting the reaction rate?The reaction rate is the pace at which the reaction takes place and the breakdown or the combination of the reactants to produce the products. The rate of reaction depends on the concentration of the reactants.
The concentration of the reactants is in direct proportion with the rate as at the beginning of a reaction there is a higher amount of substance present than at the end.
As the reaction proceeds, the reactants get consumed and their concentration decreases. As there is a decrease in concentration the rate of the reaction converting and producing the products also decreases.
Therefore, option. the rate of reaction is fast at the beginning.
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