Answer:
PLEASE MARK ME AS THE BRAINLIEST
Explanation:
According to the 2n2 rule, the maximum number of electrons in the third period = 2 x (3)2 = 18. But, the last shell cannot accommodate more than 8 electrons so, the number of electrons in third period is 8. Hence, the number of elements is also 8.
Which of the following are true for an element? (i)Atomic number= number of protons + number of electrons (ii)Mass number = number of protons+ number of neutrons (iii)Atomic mass= number of protons= number of neutrons (iv)Atomic number = number of protons = number of electrons
Answer:
ii and iv
Explanation:
atomic mass is the sum of protons and neutrons
protons ( postively charged) usually have the same number like electrons( negatively charged)
Cuál es tejidos conforman el sistema de tejido fundamental
Explanation:
Los tejidos que conforman el tejido fundamental son los siguientes:
-Parénquima
-Colénquima
-Esclerénquima.
El tejido fundamental constituye la parte principal del cuerpo de la planta porque intervienen en funciones tan importantes para el desarrollo y sostenimiento de la planta como el proceso de la fotosíntesis, el almacenamiento de agua y de nutrientes .
PLZ HELL ME WITH MY WORK
Answer:
Ba
Explanation:
In the following acid-base reaction,
Cl- is the
HCI(g) + H2O(l) →H30+(aq) + Cl(aq)
acid
base
conjugate
base
Answer:
conjugate base
Explanation:
The following equation is given in this question:
HCI(g) + H2O(l) → H30+(aq) + Cl-(aq)
In accordance to Brønsted–Lowry acid–base theory, an acid is a substance that loses an hydrogen ion (H+) or proton in an aqueous solution. This theory further indicated that the substance formed after an acid loses its hydrogen ion is called a CONJUGATE BASE.
In the above equation, HCl is the acid because it loses H+ while the substance formed after the loss of H+, which is Cl- is a conjugate base.
Balance the following chemical equations.
Fe + H2S04 ------->Fe2(SO4)3 + H2
C2H6 + O2-------> H2O + CO2
KOH + H3PO4 ------->K3PO4 + H2O
SnO2 + H2-------> Sn + H2O
NH3 + O2 ------->NO + H2O
KNO3 + H2CO3-------> K2CO3 + HNO3
B2Br6 + HNO3 ------->B(NO3)3 + HBr
BF3 + Li2SO3 ------->B2(SO3)3 + LiF
9. (NH4)3PO4 + Pb(NO3)4-------> Pb3(PO4)4 + NH4NO3
SeCl6 + O2 ------->SeO2 + Cl2
Answer:
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Explanation:
1.37 gram of cupric oxide on reduction with hydrogen gas gives 1.098gram of copper and in next experiment 1.17 gram of copper produce 1.476gram of copper oxide illustrate this satisfy law of definite proportion
Answer: This satisfies the law of definite proportion or constant proportion and it can be proven below.
Explanation:
The law of constant or definite proportion states that all pure samples of the same compound no matter how they are made; are made up of the same elements combined in the same proportion by mass. The can be verified by finding the ratio of copper to oxygen in the both experiment listed above.
In the first experiment:
1.37 g of cupric oxide contains 1.098 g copper therefore oxygen = 1.37 − 1.098
=0.272 g
The ratio of copper to oxygen is=
1.098 ÷ 0.272
= 4:1
In the SECOND or next experiment:
1.476 g of cupric oxide contains 1.17 g copper Therefore oxygen = 1.476−1.17
=0.306g
The ratio of copper to oxygen is =
=1.176 ÷ 0.306
=3.8:1
Which is approximately≃4:1.
In conclusion, despite the different methods of the experiments, composition of copper of copper in the two different samples are the same and the cupric oxide obtained from different sources contain the same elements ( copper and oxygen) combined in the SAME ratio.
How many moles of electrons is required to deposit 5.6g of iron from a solution of iron (2) tetraoxosulphate(6)
Answer:
0.20 mol
Explanation:
Let's consider the reduction of iron from an aqueous solution of iron (II).
Fe²⁺ + 2 e⁻ ⇒ Fe
The molar mass of Fe is 55.85 g/mol. The moles corresponding to 5.6 g of Fe are:
5.6 g × 1 mol/55.85 g = 0.10 mol
2 moles of electrons are required to deposit 1 mole of Fe. The moles of electrons required to deposit 0.10 moles of Fe are
0.10 mol Fe × 2 mol e⁻/1 mol Fe = 0.20 mol e⁻
0.20 mol of electrons is required to deposit 5.6g of iron from a solution of iron (2) tetraoxosulphate(6)
The reduction of iron from an aqueous solution of iron (II).
[tex]Fe^{+2} +2e^{-} \rightarrow Fe[/tex]
The formula for number of moles is as follows:-
[tex]Number \ of \ moles=\frac{Mass}{Molar\ mass}[/tex]
The molar mass of Fe is 55.85 g/mol. The moles corresponding to 5.6 g of Fe are:
[tex]5.6 g \times\frac{1\ mol}{55.85\ g} = 0.10 \ mol[/tex]
2 moles of electrons are required to deposit 1 mole of Fe. The moles of electrons required to deposit 0.10 moles of Fe are:-
[tex]0.10 mol Fe\times\frac{2\ mol\ e^{-} }{1\ mol\ e^{-}} = 0.20 \ mol e^{-}[/tex]
Hence, 0.20 mol of electrons is required to deposit 5.6g of iron.
To know more about:-
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Help me please
The options are
A. Translation
B. Rotation
C. Enlargement
D.reduction
Answer:
C. Enlargement
Explanation:
Which of the following elements would have the largest electronegativity value?
O cesium
Olithium
O carbon
O sodium
What is the name of the compound with the formula B2C14?
Answer:
Diboron tetrachloride ---> B2Cl4
Which particles have about the same mass?
O A. Neutrons and protons
O B. Electrons and protons
O C. Electrons and neutrons
O D. Electrons, neutrons, and protons
SUBMI
Answer:
A
Explanation:
Electrons are significantly smaller than neutrons and protons.
Electrons have a diameter of less than 10^-16 centimeters, whereas protons and neutrons have a radius of about 10^-13 centimeters.
. Why a chlorine atom with an atomic number of 17 will be negatively charged when its valance shell gains an electron.
Explanation:
When chlorine bonds and becomes stable, (had a full outer electron shell), because we know that chlorine has 7 electrons in it’s outer shell, it requires 1 to gain noble gas structure. So, when if bonds with an element and then becomes stable, the gaining of an electron means it becomes a negatively charged ion. (an ion being a charged particle.)
Element 'X' forms a chloride with the formula XCl2, which is a solid with high melting point. X would most likely be in the same group of the periodic table as:
I) Si
2) Al
3) Mg
4) Na
pls pls answer fast
Answer:
Mg
Explanation:
Mg forms 2+ ions and mgcl2 has a melting point over 700°C I believe.
If a quantity of this substance existed as a solid at a pressure of 0.75 atm and a temperature of 50°C, what phase
change(s) would occur if the temperature increased to 500°C?
a. Freezing and deposition
b. Melting and freezing
c. Condensation and sublimation
d. Melting and vaporization
Determine which elements or compounds are products in the
follow reaction equation:
Answer: D is the answer since it is the product of this equation
Explanation: HOPE I AM RIGHT AND IT HELPS!!!
need more explanation feel free to comment in the comment box
Nồng độ mol của 200ml dung dịch Nacl chứa 0,5 mol chất tan là :
Answer:
Explanation:
2,5M
Answer:
2,5m
Explanation:
c=n:v
please help me with this
Answer:
a. B
b. C
c. A
d. A
e. B
f. -266
g. B and D
How many Calcium (CA) atoms are in carbon tetrachloride
Answer:
5
Explanation:
Carbon tetrachloride has molecular formula as CCl4 , so from this it is evident that there are 4 atoms of Chlorine & 1 atom of carbon is present, in total 5 molecules are present in carbon tetra
Answer:
its 5
Explanation:
¿Que es bacteria y un virus ?
es para hoy por favor ayúdeme
i) Las bacterias son organismos microscópicos unicelulares que prosperan en diversos entornos. Estos organismos pueden vivir en el suelo, el océano y dentro del intestino humano.
ii) Un virus es un agente infeccioso submicroscópico que se replica solo dentro de las células vivas de un organismo. Los virus infectan todas las formas de vida, desde animales y plantas hasta microorganismos, incluidas bacterias y arqueas.
phosphorus react with carbon
Answer:
Phosphorus atoms can bond with oxygen atoms to form ester groups. These can bond with carbon atoms, yielding a large number of organic phosphorus chemicals. These are found in many important biological processes
Which of the following about a balanced chemical reactions is
NOT true?
O A properly written chemical equation will include the states of matter
for every substance in the reaction.
O The number of atoms of each element must be the same for both
reactants and products.
A balanced chemical equation must follow the Law of Conservation
of Matter
A balanced chemical equation must always include coefficients on
every reactant and product.
Answer:
A balanced chemical equation must always include coefficients on every reactant and product.
Explanation:
A balanced chemical equation does not need to include coefficients on every reactant and product.
For example, below is a balanced chemical equation in which the reactants and the products have no coefficients whatsoever:
NaOH(aq) + HCl (aq) -----> NaCl (s) + H2O (l)
Of course, a properly written chemical equation must include the states of matter of all the substances in the reaction and the number of atoms of each element must balance both in the reactant and product sides of the equation. Generally, a balanced chemical equation must obey the law of conservation of matter which opines that matter can neither be created nor destroyed but can only be converted from one form to another.
Hence, that a balanced chemical equation must always include coefficients on every reactant and product is not true.
What volume of 0.200 M Na2CO3 (Mm = 106 g/mol) solution contains 53.0 g of Na2CO3?
Question 1 options:
0.200 L of solution
0.400 L of solution
0.500 L of solution
1.60 L of solution
2.50 L of solution
Answer:
volume in Liter = 2.50 L
Explanation:
Given:
Na2CO3 = 0.2 M
Molar mass of Na2CO3 = 106 g/mol
Mass of Na2CO3 solution = 53 gram
Find:
Volume of Na2CO3
Computation:
Number of mol of Na2CO3 = (53 g) / (1.06 x 10² g/mol)
Number of mol of Na2CO3 = 0.5 mol
M = Number of mol / volume in Liter
0.2 = 0.5/ volume in Liter
volume in Liter = 0.5 / 0.2
volume in Liter = 2.50 L
write electronic configuration of chlorine in its ionic state?
Answer:
1s2 2s2 2p6 3s2 3p6
Explanation:
Chlorine is a groups 17 element. The halogens for ions by accepting one electron to form univalent negative ions.
Since chlorine normally contains seventeen electrons, the chloride ion consists of eighteen electrons.
Hence the electronic configuration of chlorine ion is; 1s2 2s2 2p6 3s2 3p6.
1. Necesitas un "cubo concentrado" (de esos que se usan para sazonar las comidas Maggie, ricostilla) dos vasos de vidrio o plástico y agua (caliente y fría). 2.Agrega al vaso con agua fria la mitad de un cubo concentrado y déjala reposar unos minutos. Prepara el segundo vaso con agua caliente y agrégale la otra mitad del cubo. 3. Argumenta tus observaciones en relación con lo observado y con la teoria vista. ¿Como influye la temperatura en este experimento?
Write the empirical formula for the hydrated KAl(SO4)2, based on your experimental results and answer to Question 2. Show all work including units.
Hint: if the ratio of moles of H2O to moles of anhydrous KAl(SO4)2 was 4, then the empirical formula would be: KAl(SO4)2•4H2O.
Answer to Question 2:
Ratio of 2:3
Answer:
Therefore mole ratio is [tex]H_{2}O[/tex] : [tex]KAl(SO_{4} )_{2}[/tex] is 12 :1
Empirical formula is [tex]KAl(SO_{4} )_{2}. 12 H_{2}O[/tex].
Explanation:
The chemical formula of a hydrate
Moles of anhydrous [tex]KAl(SO_{4} )_{2}[/tex]
Molar mass of [tex]KAl(SO_{4} )_{2}[/tex] = 258.21 g /mol
Mass of anhydrous [tex]KAl(SO_{4} )_{2}[/tex] = [mass of aluminum cup + alum after 2nd heating] –[ mass of empty cup]
= 3.5 g – 2.4 g
= 1.1 g
Moles of [tex]KAl(SO_{4} )_{2}[/tex]= mass / molar mass
= 1.1 g / 258.21 g per mol
= 0.00426 mol [tex]KAl(SO_{4} )_{2}[/tex]
The mole ratio of the H2O to [tex]KAl(SO_{4} )_{2}[/tex]
Mole ratio = moles of H2O/ moles of [tex]KAl(SO_{4} )_{2}[/tex]
= 0.05 mol H2O / 0.00462 mol [tex]KAl(SO_{4} )_{2}[/tex]
= 11.7
We can round the 11.7 to closest whole number = 12
Therefore mole ratio is [tex]H_{2}O[/tex] : [tex]KAl(SO_{4} )_{2}[/tex] is 12 :1
Empirical formula = [tex]KAl(SO_{4} )_{2}. 12 H_{2}O[/tex]
So we have 12 moles of water as the water of hydration in the empirical formula.
Alum hydrate is that the white crystalline solid after heating it'll start melting due to the water of hydration present in it then again solid will remain within the aluminum cup once all the water is given off within the sort of vapors.
b) if the scholar used 2.20 g of the sample but within the calculation, he started with 2.0 g sample then
when the mass of water is calculated using this data the mass of water is going to be higher therefore it gives more moles of water within the hydrate.
So the final answer is going to be artificially high.
hii pls help me to balance chemical equation
calcium hydroxide + hydrochloric acid ------> calcium chloride + water
Answer:
1 Ca(OH)2 + 2 HCl ---> 1 CaCl2 + 2 H2O
The acid dissociation constant, Ka, of HSO4- is 1.2 × 10-2. What does the Ka value indicate about this compound?
A.
HSO4- is a weak base.
B.
HSO4- is a strong acid.
C.
HSO4- is a weak acid.
D.
HSO4- is a strong base.
Answer:
The answer is HSO4- is a weak acid which will be C
The acid dissociation constant, ka, of HSO4- indicates that it is a strong acid. Details about acid dissociation constant can be found below.
What is acid dissociation constant?The acid dissociation constant denoted by Ka is the measure of the strength of an acid.
The dissociation constant of an acid is used to identify strong acids from their weak counterparts. Strong acids have high Ka values while weak acids have low Ka values.
According to this question, the Ka of HSO4- is 1.2 × 10-², which is quite high.
Therefore, the dissociation constant, ka, of HSO4- suggests that it is a strong acid.
Learn more about acid dissociation constant at: https://brainly.com/question/4363472
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Which we events will happen if more H, and t, are added to this reaction
when it is in equilibrium?
A. The rate of the backward reaction will increase
The rates of formation of He and I will increase
0. The rate of the forward reaction will increase
D. The rate of formation of HI will increase
Answer:
its is letter c is your answer
Explanation:
I hope this help
Consider the half reactions below for a chemical reaction.
ZnZn2+ (aq) + 2e
Cu?" (aq) + 2e → Cu(s)
What is the overall equation for this chemical reaction?
Zn(s)+ Cu?* (aq) —>Zn2+ (aq) + Cu(s)
O Zn(s) + Cu2+ (aq) — Cu2+ (aq) + 2e-
O Zn2*(aq) + Cu(s) —> Cu2* (aq) + Zn(s)
O Zn2+ (aq) + 22 —> Cu2(aq) + 2e
Answer:
Option A:
Zn(s) + Cu^(2+) (aq) → Cu(s) + Zn^(2+)(aq)
Explanation:
The half reactions given are:
Zn(s) → Zn^(2+)(aq) + 2e^(-)
Cu^(2+) (aq) + 2e^(-) → Cu(s)
From the given half reactions, we can see that in the first one, Zn undergoes oxidation to produce Zn^(2+).
While in the second half reaction, Cu^(2+) is reduced to Cu.
Thus, for the overall reaction, we will add both half reactions to get;
Zn(s) + Cu^(2+) (aq) + 2e^(-) → Cu(s) + Zn^(2+)(aq) + 2e^(-)
2e^(-) will cancel out to give us;
Zn(s) + Cu^(2+) (aq) → Cu(s) + Zn^(2+)(aq)
what are some of the uses of halogens?
Answer:
Halogens are used in, water and sanitation, plastics, pharmaceutical, pulp and paper, textile, military and oil industries. Bromine, chlorine, fluorine and iodine are chemical intermediates( bleaching agents and disinfectants). Chlorine is used to purify water. Chlorine also is part of salt, sodium chloride, which is one of the most widely used chemical compounds. Fluorine is used in fluorides, which are added to water supplies to prevent tooth decay.
hopes this helps~
Answer:
What are some uses of halogen elements? Chlorine is used to purify water. Chlorine also is part of salt, sodium chloride, which is one of the most widely used chemical compounds. Fluorine is used in fluorides, which are added to water supplies to prevent tooth decay.
Explanation:
Halogen, any of the six nonmetallic elements that constitute Group 17 (Group VIIa) of the periodic table. The halogen elements are fluorine (F), chlorine (Cl), bromine (Br), iodine (I), astatine (At), and tennessine (Ts). They were given the name halogen, from the Greek roots hal- (“salt”) and -gen (“to produce”), because they all produce sodium salts of similar properties, of which sodium chloride—table salt, or halite—is best known.
Because of their great reactivity, the free halogen elements are not found in nature. In combined form, fluorine is the most abundant of the halogens in Earth’s crust. The percentages of the halogens in the igneous rocks of Earth’s crust are 0.06 fluorine, 0.031 chlorine, 0.00016 bromine, and 0.00003 iodine. Astatine and tennessine do not occur in nature, because they consist of only short-lived radioactive isotopes.
