Explanation:
If the reaction is endothermic as written, an increase in temperature will cause the forward reaction to occur
1. The atomic symbol of aluminum is written as 2713Al. What information do you get from it?
Answer:
its mass number and atomic number
Explanation:
atlmic number(subscript)=13
mass number(superscript)=27
What is the oxidation number of carbon in CO2
Answer: Since oxygen is in group 6 on the periodic table, its valency is
2 −
and hence so is its oxidation number.
But there are 2 oxygen atoms for each carbon atom so the total negative charge due the oxygen is
4 −
But since a molecule must have a net charge of zero in the free form, it implies that the oxidation number of the carbon atom must then be
+ 4
To make a table of elements, dmitri
The question is incomplete, the complete question is;
To make a table of the elements, dimitri Mendeleev sorted the elements according to their?
Answer:
Atomic weights
Explanation:
Dimitri Medeleeve is a Russian scientist who worked assiduously on the project of developing a system of classifying all the elements. His periodic table was filled with spaces as many atoms weren't yet discovered. 'Eka' prefix was used to name some elements whose properties closely resembled that of their predecessors in Mendeleev's system of classification.
The dependence of the atomic properties on the weight of the atom was the basis for Mendeleeves' original classification. According to Medeleeve, elements having similar chemical properties are also expected to have similar atomic weights and their atomic weights was found to increase regularly.
The Mendeleeve concept of periodic arrangement of elements is the closest precursor of the modern periodic table as it is used in chemistry. Mendeleev arranged the elements in order of increasing relative atomic mass .
To what temperature should 2.3L of a gas at 25degree Celsius be heated in order to expand its volume to 4 L under constant pressure
Answer:
518.52K
Explanation:
Charles law, which describes the direct relationship between the volume and the temperature of a gas when the pressure is constant, will be used for this question. The Charles law equation is:
V1/T1 = V2/T2
Where; V1 is the volume of the gas at an initial state (Litres)
T1 is the absolute temperature of the gas at an initial state (Kelvin)
V2 is the volume of the gas at a final state (Litres)
T2 is the absolute temperature of the gas at a final state (Kelvin)
According to the question, V1 = 2.3L, T1 = 25°C, V2 = 4L, T2 = ?
We need to convert the temperature to the absolute temperature unit in Kelvin (K) i.e.
T(K) = T(°C) + 273.15
T(K) = 25°C + 273.15
T1 (K) = 298.15K
To find for T2 in the equation, we make T2 the subject of the formula:
T2 = V2 × T1 / V1
T2 = 4 × 298.15 / 2.3
T2 = 1192.6/2.3
T2 = 518.52
Thus, the temperature must be heated to 518.52K in order to expand to a volume of 4L. This answer is in accordance to Charles law that the volume increases with increase in temperature and vice versa.
Name a Solid, Liquid, and a Gas. Solid: Liquid: Gas:
Answer:
Gas - Steam
Solid - Rock
Liquid - Juice
Answer:
Solid: Ice
Liquid: Water
Gas: Steam or Water vapor
Explanation:
This is a common example to answer your question. Some other examples are:
-most metals(ex: iron, tin, copper, gold) These are solids
-milk, juice, hot chocalate, any soda drink These are liquids
-hydrogen, helium, carbon dioxide, oxygen These are gases
Hope this helps!
what happens when ca no3 2 is heating it gives CaO ,NO2 and 02
Answer:
balanced equation:
2Ca(NO3)2 (aq)-----> 2CaO (s) + 4NO2 (g) + O2 (g)
So heating 2 moles of Ca(NO3)2 gives 2 moles of CaO, 4 moles of NO2 and 1 mole of O2. This is a heat decomposition reaction. It gives a white precipitate (CaO), and brown pungent gas (NO2).
Answer:
The balanced equation of the reaction is below.
Explanation:
2Ca(NO3)2 -----> 2CaO + 4NO2 + O2.
Which of the following elements does not lose an electron easily? NA F MG AL
Answer:
F
EXPLANATION
Among the given elements fluorine(F)can not lose electrons easily because of its high electron affinity, high nuclear charge and high electronegativity.
Answer:
F
Explanation:
it won't lose electron , rather it would gain electron to complete its octate......
Electronic Configuration of F = 2,7
So F will gain 1 electron ....
The cell potential of an electrochemical cell is positive. What does that tell
you about the redox reaction?
A. The reduction part of the reaction occurs at the anode.
B. The oxidation part of the reaction occurs at the cathode.
C. The reaction is spontaneous.
O D. The reaction is nonspontaneous.
Answer:
A. The reduction part of the reaction occurs at the anode
Answer:
A
Explanation:
To dissolve in water, aluminum (AI) should form a compound with
oxide (O2-).
sulfide (S2-).
nitrate (NO,-).
phosphate (POP).
Answer:
Explanation:
Nitrate of most of the elements are water soluble . Aluminium nitrate is also one of them . Aluminium nitrate is easily dissolved in water . It forms hydrated salt whose formula is as follows
Al( NO₃ )₃ . 9H₂O
It is a white crystalline salt . It is also soluble in alcohol.
Which statement describes an electron?
Answer:
The statement that describes an electron is "It has a negative charge and is located in orbitals around the nucleus." Electrons are the smallest of the three particles that make up atoms
Explanation:
Electrons are found in shells or orbitals that surround the nucleus of an atom
Electrons are the sub-atomic particles that carry a negative charge over them. In the atom, the electrons are found in the orbitals or the shells around the nucleus. Thus, option D is correct.
What are electrons?
Electrons are the smallest sub-atomic particle that has been known to carry a negative charge and are found in the orbitals of the atom. The charge carried by an electron is 1.602 x 10⁻¹⁹ coulomb and is small than the proton and neutron.
They revolve around the nucleus in their orbits and exhibit the properties of waves and matter. The number of electrons and protons are the same in a neutral atom which makes the atomic number.
Therefore, the electrons have been known to carry a negative charge that revolves in orbit around the nucleus.
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Your question is incomplete, but most probably your full question was, Which statement describes an electron?
It has a positive charge and is located in the nucleus. It has a positive charge and is located in orbitals around the nucleus. It has a negative charge and is located in the nucleus. It has a negative charge and is located in orbitals around the nucleusWhat statement describes the cause for sibling rivalry between both brothers? The older son shared his fears about providing financial support for the family after graduating. The sons challenged each other by competing for the highest grade point average that year. The younger son expressed feelings about his parents showing favoritism to his older sibling. The sons disagreed over the handling of family tasks once the younger son heads off to college
Answer:
c
Explanation:
you took the test on edge
The statement describes the cause for sibling rivalry between both brothers is The younger son expressed feelings about his parents showing favoritism to his older sibling. Hence , Option (C) is correct.
What is Sibling rivalry ?Sibling rivalry is the jealousy, competition and fighting between brothers and sisters.
It is a concern for almost all parents of two or more kids.
Problems often start right after the birth of the second child.
Sibling rivalry usually continues throughout childhood and can be very frustrating and stressful to parents.
Therefore, The statement describes the cause for sibling rivalry between both brothers is The younger son expressed feelings about his parents showing favoritism to his older sibling. Hence , Option (C) is correct.
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Which of these is an ex
example of a composite material?
Answer:
A composite material is a material made from two or more constituent materials with significantly different physical or chemical properties that, when combined, produce a material with characteristics different from the individual components.
Explanation:
you're welcome
write chemical equation for the following decomposition reactions. Aluminum oxide(s) decomposes when electricity is passed through it.
Answer:
2Al2O3 (l) ---> 4Al (l) + 3O2 (g)
Explanation:
The reaction is the electrolysis of aluminium oxide. It decomposes aluminium oxide (Al2O3) into aluminium metal (Al) and Oxygen (O2). In this process, aluminium oxide is molten (liquid state) so that ions can move to complete the electricity circuit.
Al2O3 (l) ---> Al (l) + O2 (g)
Balance the equation:
2Al2O3 (l) ---> 4Al (l) + 3O2 (g)
The steady state vital to life is possible because:________
a. the cell cannot convert energy from one form to another.
b. all cells are autotrophic.
c. all reactions are exothermic.
d. the cell continually takes up energy from the environment.
e. all reactions are at equilibrium.
Answer: The correct answer is e) all reactions are at equilibrium.
Explanation: In order for cellular vitality to develop, it is necessary for it to be in energetic balance with the environment, that is, to give and receive energy with the environment that surrounds it through endothermic or exothermic reactions. That is why the development of life is considered a system that constantly exchanges with the environment. In turn, that the cell unit maintains a balance with the environment causes homeostasis to occur among the whole organism.
someone help me please....
Answer:
i- In beaker A, sodium chloride will dissolve with water.
and in beaker B, there will be no reaction.
ii- sodium chloride is soluble in water, while sand is insoluble.
iii- The reaction can be increased by adding more sodium chloride to the beaker.
iv- The sodium chloride will no longer dissolve in the water.
What mass of oxygen gas contains the same number of moles as 56g of sulphur? (Relative atomic mass: S = 32, O = 16) A) 0.56g B)5.6g C)56g D)560g
Answer:
The answer is option C
Explanation:
To calculate the mass of oxygen gas we must first find the number of moles of sulphur
Molar mass = number of moles (n) / mass
n = mass / Molar mass
From the question
Molar mass (M) of Sulphur = 32g/mol
mass = 56g
n( Sulphur) = 56/32 = 1.75mol
Since the moles of oxygen and sulphur are the same
M(O2) = 16 × 2 = 32g/mol
Mass of oxygen = molar mass × moles
= 32 × 1.75
= 56gHope this helps you
An electron in a hydrogen atom moves from level 1 to level 4. The electron then drops from level 4 to level 2. Which statement describes the most likely result?
A. The energy absorbed in the first move equals the energy released in the second move.
B. The energy absorbed in the first move is greater than the energy released in the second move.
C. The energy released in the first move equals the energy absorbed in the second move.
D. The energy released in the first move is greater than the energy absorbed in the second move.
Answer:
B. The energy absorbed in the first move is greater than the energy released in the second move.
Explanation:
It takes large amounts of energy for a electron to jump energy levels and the further it moves, the more it takes.
Answer:
B
Explanation:
The energy absorbed in the first move is greater than the energy released in the second move.
Energy from a reaction was determined to be 3870 J using a water calorimeter, when burning 9.00 grams of H2. What is the total enthalpy of the reaction?
Answer:
860 J / mol
Explanation:
Enthalpy = Energy / no. of moles
no. of moles = mass / molar mass
Take the atomic mass of H = 1.0,
molar mass of H2 = 1.0 x 2
= 2.0
no. of moles of H2 = 9.00/2
= 4.5 mol
Hence,
Enthalpy = 3870 / 4.5
=860 J / mol
answer the question briefly: How can atom collapse and why are atoms stable?
The nuclei of atoms become unstable when the repelling forces of the protons cannot be balanced by the number of neutrons in the nucleus. It then re-arranges itself randomly to a more stable configuration by emitting any of a series of particles. During radioactive decay, an atom does not collapse.
Since an atom is mostly empty space - that is it’s nucleus is relatively distant from the electron shells so, in the presence of extreme forces such as gravity inthe collapse of a large star, the inward pressures on the atom overcome the natural balance of the atomic structure and the ‘empty space’ disappears as nuclei are mashed together by the intense pressures and a neutron star is formed. Under even more external pressure, even the neutron star can collapse to form a black hole.
12. Classify the following as conduction, convection or radiation. a. A steel mug kept near a stove becomes hot after some time. b. The metal handlebars of a bicycle are colder than plastic hand grips. c. Some people get sunburn when they go out in the sun for a long time. d. The paper kept above a candle flame starts burning after some time.
A - convection
B - conduction
C - radiation
D - convection
how to make a salt by neutralization reaction
Answer:
Acid+Base=Salt+water
This is the formula of neutralization reaction.
According to this formula you can make salts by reacting an acid with a base.
Hope this helps ❤❤❤.
An atom of an element is shown by the model. A gray circle is surrounded by 4 concentric circles. The innermost circle has gray dots at the north and south positions; the second ring has 8 equally spaced dots, aligning with the inner ring at north and south; the third ring has 14 dots, equally spaced, aligned with the other rings at north and south; the outer ring has dots at north and south. How is this model useful? It shows how electrons are distributed in the shells of an iron atom. It shows how electrons are distributed in the shells of a cobalt atom. It shows how orbitals are distributed in the shells of an iron atom. It shows how orbitals are distributed in the shells of a cobalt atom.
The correct answer is A. It shows how electrons are distributed in the shells of an iron atom.
Explanation:
In the model described, the circles represent the orbitals or shells of the atom, while the dots represent the distribution of electrons (negatively charged sub-particles). Additionally, the description shows the general electronic configuration of this atom is 2, 8, 14, 2, which means in the first orbital there are two electrons, in the second there are eight electrons, in the third, there are fourteenth electrons and in the fifth orbital there are two electrons. This electronic configuration occurs in the atoms of iron. Also, this differs from Cobalt because in cobalt the third orbital has 15 electrons. Thus, the model "shows how electrons are distributed in the shells of an iron atom".
Answer:
a. it shows how electrons are distributed in the shells of an iron atom
Explanation:
edge 2021
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suppose a 22.092 g sample of 1 1 mixture of acetylferrocene and ferrocene was sepeerated by column chromatography and the recovered fractions weighed 9.017 g acetylferrocene and 8.075 g ferrocene what was the eprcent recovery of acetyl ferrocene
Answer:
Percentage recovery of acetylferrocene = 81.6%
Explanation:
Mass of the sample mixture = 22.092 g
Ratio of mixture of acetylferrocene and ferrocene = 1 : 1
This means that the sample conatains equal amounts of acetylferrocene and ferrocene.
Therefore the mass of each sample in the mixture = 22.092 g / 2 = 11.046 g
Mass of acetylferrocene recovered = 9.017 g
Percentage recovery of acetylferrocene = (mass of recovered/ mass in sample) * 100%
Percentage recovery of acetylferrocene = (9.017 g / 11.046 g) *100%
Percentage recovery of acetylferrocene = 81.6%
calculate the mass of sodium sulphate required to prepare its 20%of solution in 100 g ofwater
Answer:
25 g
Explanation:
Mass percent implies the mass of solute dissolved in a solution
Mass percent = mass of solute/mass of solute + mass of solvent × 100/1
Since mass percent concentration= 20%
Mass of solvent = 100g
Let mass of solute = x
Hence;
20 = x/x +100 ×100/1
20/100= x/x + 100
0.2 = x/x + 100
0.2(x + 100) = x
0.2x + 20 = x
20 = x - 0.2x
20 = 0.8x
x= 20/0.8
x= 25 g
D Serum Levels Of 4 Mcg/mL, Calculate The Dose, In Milligrams, For A 120-lb Patient That May Be Expected To Result In A Blood Serum Gentamicin Level Of 4.5 Mcg/mL. This problem has been solved! See the answer If the administration of gentamicin at a dose of 1.75 mg/kg is determined to result in peak blood serum levels of 4 mcg/mL, calculate the dose, in milligrams, for a 120-lb patient that may be expected to result in a blood serum gentamicin level of 4.5 mcg/mL.
Answer:
The patient requires a dose of 107.2 mg of gentamicin
Explanation:
A dosage of 1.75 mg per Kilogram body weight results in blood serum levels of 4.5 mcg/mL
This means that; 1.75 mg/ kg = 4.0 mcg/mL
Therefore, dosage of gentamicin in mg/kg that will result in 4.5 mcg/mL blood serum level = (1.75 mg/Kg * 4.5 mcg/mL) / 4.0 mcg/mL
Dosageof gentamicin = 1.97 mg/Kg
1-lb = 0.453592 Kg
Weight of 120-lb patient in Kg = 120 * 0.453592 = 54.43 Kg
Dose in mg required by patient = 1.97 mg/Kg * 54.43 Kg = 107.2 mg
Therefore, the 120-lb patient requires a dose of 107.2 mg of gentamicin to result in a blood serum level of 4.5 mcg/mL
Ammonia is produced when a mixture of of ammonium chloride and substance C is heated. What is substance X?
What is the molarity of 0.25 moles of FeCl3 dissolved in 120 ml of solution?
Answer:
Molarity = 2.0833 M (Approx)
Explanation:
Given:
Number of moles (n) = 0.25
Volume of solution = 120 ml = 0.12 L
Find:
Molarity
Computation:
Molarity = Number of moles (n) / Volume of solution.
Molarity = 0.25 / 0.12
Molarity = 2.0833 M (Approx)
Earth’s outermost layer is separated into a dozen or more large and small slabs, called _______. A. continental crust B. tectonic plates C. granite slabs D. Pangea
Answer:
Tectonic Plates
Explanation:
Answer:
Tectonic plates
Explanation:
Label the following as either an Element, Compound, or Mixture.
Answer:
27. Element (Because it contains all same atoms)
28. Compound (It contains atoms held together through chemical bonds)
29. Element (it contains all same atoms)
33. Mixture (It contains different atoms but they are not held together through chemical means)
34. Compound (Different atoms held together through chemical means)
35. Mixture (Mixture of elements and compounds)
30. Element (it contains all same atoms)
31. Mixture (Mixture of elements and compounds)
32. Element (Contain all same atoms although held together through chemical means they are not compounds)
Na-23 has 12 neutrons. What is it’s atomic number?
Answer:
11 Protons
Explanation:
Na-23 shows the mass of the element as 23. Therefore subtract 12 neutrons from the mass to get # of protons which is = to atomic #.
The atomic number of 23-Na is 11. It can be calculated from the number of protons present in the nucleus of an atom.
The atomic number is a fundamental property of an element and represents the number of protons found in the nucleus of an atom. It uniquely identifies each element on the periodic table. In a neutral atom, the atomic number also indicates the number of electrons present in the atom, as the number of protons and electrons in an atom are equal.
For example, hydrogen has an atomic number of 1, indicating that it has one proton in its nucleus. Oxygen has an atomic number of 8, indicating that it has eight protons in its nucleus.
The atomic number determines the element's position in the periodic table and provides important information about its properties and behavior.
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