Answer:
The valence shell (the 3s and 3p sublevels) contains six electrons, but it needs eight to become stable. Think of the octet rule. Therefore a sulfur atom will gain two electrons to form the sulfide anion with a charge of 2− , with the symbol S2− .
On the periodic table, the period number can identify the number of energy levels an element will contain.
False
True
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Help ASAP plzzzz!!!!!!!!
Answer:
Granite Solid
Milk Liquid
Neon is gas
Wood Is solid
Paper is solid
Helium is Gas
Water is liquid
Air is Gas
Alcohol is liquid
Metal is solid
Nitrogen is gas
Juice is liquid
Oil is liquid
Water Vapor is Gas
Brick is Solid
Propane is Gas
Fabric is solid
Gasoline is Liquid
Explanation:
Hope Dis helped :D :3
Which of the following is true about pure substances? A. A pure substance has the same chemical properties throughout. All pure substances are unable to be separated by any means. c. A pure substance can only be made up of one kind of atom. D. A pure substance can always be separated by physical means.
Answer:first one
Explanation:
A pure substance has same chemical properties throughout , it cannot be separated by any means and it is made up of one kind of atom.
What are chemical properties?
These properties are defined as those properties which become evident during or after a chemical reaction after the identity of the substance is changed during chemical reaction.
These properties cannot be determined externally just by viewing the substance ,these change immensely after a substance undergoes a chemical change.These are used for identification of unknown substances and for building up chemical classifications.
The major chemical properties are flammability,toxicity,reactivity,acidity and heat of combustion.For a chemical property to be apparent , it is necessary that the structure of the substance is altered.
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Un estudiante preparo 200 ml de solución de acetato de potasio (CH3COOH ; Masa molar = 98 g/mol ; Ka CH3COOH = 1,8 x 10-5), disolviendo 3,5 g de ácido, la que denomino "Solución A". Posteriormente preparo otra solución de menor concentración del mismo soluto que denomino "solución B" y para ello tomo un volumen de 5,5 ml de la solución A y agrego agua hasta 70 ml de solución. Señale el pH de solución A y B y, la concentración molar de CH3COO- en la solución b.
Answer:
mirar respuesta abajo
Explanation:
Muy bien. Antes de responder lo que piden en el problema, vamos a calcular la concentración inicial de la solución A:
1) Concentración de la solución A:
En este caso, se sabe que se usaron 3,5 g de la sal, se puede calcular los moles usando el peso molecular y la masa:
n = m/PM (1)
Aplicando tenemos:
n = 3,5 / 98 = 0,0357 moles
Conociendo los moles, podemos calcular la concentración:
M = n/V (2)
Aplicando la formula tenemos:
M = 0.0357 / 0.200 = 0.1785 M
Esta es la concentración del ácido etiquetado como "Solución A".
Ahora podemos ver la concentración de la solución B, para luego calcular las concentraciones molares de los iones en solución y sus respectivos pH.
2) Concentración del ácido en la solución B:
Con la concentración de "A", se puede determinar la concentración de la solución B. Aqui podemos esperar que sea un valor mas bajo, puesto que es una dilución la que estamos haciendo. Por lo tanto.
Si se toma 5.5 mL de la solución A, entonces:
n = 0.1785 * 0.0055 = 0.00098 moles
Con esto, se calcula la nueva concentración:
M = 0.00098 / 0.070 = 0.014 M
Esta es la concentración de la solución B. Ahora para calcular pH y concentraciones de los iones en equilibrio, hay que plantear la reacción acido base en equilibrio. Como es el mismo compuesto, usaremos la misma ecuación.
3) pH de las soluciones A y B:
Planteamos la reacción de equilibrio:
CH₃COO⁻ + H₂O <------> CH₃COOH + OH⁻ Kb
Calculando el Kb, sería asi:
Kb = Kw/Ka
Kb = 1x10⁻¹⁴ / 1.8x10⁻⁵ = 5.56x10⁻¹⁰
Ahora reescribimos la ecuación y hacemos una tabla de equilibrio:
CH₃COO⁻ + H₂O <------> CH₃COOH + OH⁻ Kb = 5.56x10⁻¹⁰
i) 0.1785 x x
eq) 0.1785-x x x
Kb = [OH⁻] [CH₃COOH] / [CH₃COO⁻]
Reemplazando nos queda:
5.56 * 10⁻¹⁰ = x² / (0.1785-x)
Y como Kb es muy pequeño, se asume que el valor de x será también pequeño, asi que podemos redondear la resta a simplemente 0.1785, quedando tan solo:
5.56 * 10⁻¹⁰ = x² / (0.1785)
x² = 5.56*10⁻¹⁰ * 0.1785
x = √9.9246*10⁻¹¹
x = 9.96*10⁻⁶ M
Esta es la concentración de [OH⁻] y [CH₃COO⁻] en la solución A.
Aplicando lo mismo para la solución B (Cambiando solo el dato de concentración) nos queda:
x = √5.56*10⁻¹⁰ * 0.014
x = 2.79x10⁻⁶ M = [OH⁻] = [CH₃COO⁻]Finalmente, para calcular pH, se calcula primero el pOH y luego el pH:
pH = 14 - pOH
pOH = -log[OH⁻]
Para la solución A:
pOH = -log(9.96*10⁻⁶) = 5
pH = 14 - 5
pH = 9En el caso de la solución B:
pOH = -log(2.79*10⁻⁶) = 5.55
pH = 14 - 5.55
pH = 8.45Espero te ayude
Elements in group to are cold alkaline earth metals what is most similar about alkaline earth metals how many protons and neutrons they have which Chemical properties he have how many total electrons they have which period They have most often found in
Answer:
explanations below
Explanation:
The alkaline earth metals are the 6 chemical elements that can be found in group two of the periodic table. These elements have a lot of properties in common, in the sense that they are generally shiny, reactive at standard temperature and pressure and they are also silvery-white. The elements are beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra)
These metals have two electrons at their orbits, which can be easily lost to form cations (with charge +2, and an oxidation state of +2)
Below are some of their details
Name: Beryllium
Number of Protons/Electrons: 4
Number of Neutrons: 5
Name: Magnesium
Number of Protons/Electrons: 12
Number of Neutrons: 12
Name: Calcium
Number of Protons/Electrons: 20
Number of Neutrons: 20
Name: Strontium
Number of Protons/Electrons: 38
Number of Neutrons: 50
Name: Barium
Number of Protons/Electrons: 56
Number of Neutrons: 81
Name: Radium
Number of Protons/Electrons: 88
Number of Neutrons: 138
Which of the following elements would be brittle?
Sulfur
Magnesium
Rubidium
Lithium
Answer:
Sulfur
Explanation:
How many hydrogen atoms are in 2h2+02—2h20?
Answer: Two hydrogen atoms
Explanation:
A water molecule (formally known as dihydrogen monoxide) is composed of two hydrogen atoms and one oxygen atom. But you can't simply take two hydrogen atoms and stick them onto an oxygen atom. The actual reaction to make water is a bit more complicated: 2H2 + O2 = 2H2O + Energy.
What would happen to the rate of a reaction if the concentration of substrate was increased after the point of saturation?
a)The reaction rate would increase.
b)The reaction rate would decrease.
c)There would be no effect.
Answer:
there would be no effect
Explanation:
Brainliest please helppppppppp
Ayour anwerser
Explanation
Answer:
chlorine manoxside
co2
Explanation:
What is the atomic number of an atom?
O the number of neutrons
O the number of electrons and neutrons
O the number of protons
the number protons and neutrons
What information does a subscript in a chemical formula provide? Choose all that apply. * The charge of that atom while in the compound How many of each atom are present in the compound How many valence electrons each element has while in the compound How many valence electrons each element starts with In ionic, the simplified ratio of atoms in relation to each other
Answer:
B. How many of each atom are present in the compound
D. the simplified ratio of atoms in relation to each other
Explanation:
In a chemical formula, chemical elements or atoms are represented by a chemical symbol for example Fe for iron and Na for sodium, and the number of each atom is represented by a subscript such as CO2, where 2 is a subscript representing 2 atoms of oxygen.
A subscript represents the number of each atom in the compound and the simplified ratio of atoms in relation to each other. The simplified ratio of atoms in relation to each other means subscript shows the contribution of both the atoms in the compound, for example: N2 + 3H2 => 2NH3, it means the subscript showing the ratio or proportionate of atoms that is 2:2 for both nitrogen and hydrogen.
The subscript is always written below and to the right of the chemical symbol.
Hence, the correct answer is "B. How many of each atom are present in the compound and D. the simplified ratio of atoms in relation to each other"
Describe how calcium and fluorine bond together to form calcium fluoride. The electron arrangement of each atom is shown.
Answer:
Detail is given below.
Explanation:
Calcium is alkaline earth metal. It has two valance electron. Thus calcium needs six more electron to complete the octet. Thus, its very easy for calcium to remove its two electron and get complete octet.
Electronic configuration of Ca:
Ca₂₀ = [Ar] 4s²
While,
Fluorine is halogen. It has seven valance electrons. It needed only one electron to complete the octet. When it combine with calcium , calcium loses two electrons thus two atom of fluorine combine with one atom of fluorine and stable compound calcium fluoride is formed.
Electronic configuration of F:
F₉ = [He] 2s² 2p⁵
Chemical equation:
Ca + F₂ → CaF₂
combined aggregation of minerals
Answer:
Rocks
Explanation:
The combined aggregation of minerals are called rocks. There are three types of rocks Igneous Rocks, sedimentary rock, and metamorphic rocks.
Rocks are formed due to the repetitive, orderly, geometrical internal arrangement of minerals. Minerals undergo several processes such as weathering, crystallization, erosion, and sedimentation to form rocks.
Hence, the combined aggregation of minerals is called rocks.
the ability for a substance to rust is
a. oxidation
b.rustability
c.magnetic attraction
d.reactivity
Answer:
i think it is letter b. rustability but not so sureeee
Help pleaI’ll give brainliest
Which element has the
greatest number of valence electrons available for bonding?
O selenium
Oboron
O calcium
O chlorine
How does a heat affect the chemical reaction?
Answer:
Increasing the temperature increases reaction rates because of the disproportionately large increase in the number of high energy collisions. It is only these collisions (possessing at least the activation energy for the reaction) which result in a reaction.
Explanation:
IUPAC name for BaSO3
Answer:
Barium Sulfite
Explanation:
Barium Sulfite
The IUPAC name for BaSO₃ is barium sulfite.
"Ba" stands for barium, which is the chemical symbol for the element with atomic number 56. Barium is an alkaline earth metal and belongs to Group 2 of the periodic table.
"SO₃" stands for sulfite, which is a polyatomic ion composed of one sulfur atom (S) and three oxygen atoms (O). The chemical formula for the sulfite ion is SO₃²⁻. The sulfur atom in the sulfite ion has a +4 oxidation state.
When barium (Ba) reacts with the sulfite ion (SO₃²⁻), they combine to form barium sulfite (BaSO₃). The balanced chemical equation for the reaction is:
Ba²⁺ + SO₃²⁻ → BaSO₃
Barium sulfite is an ionic compound, where the Ba²⁺ ion and the SO₃²⁻ ion are held together by electrostatic attractions (ionic bonds). In its solid form, barium sulfite appears as a white crystalline powder.
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Which materials sink in water? Hint: There is more than one nightanswer. Rubber Wooden Ball Ice Granite Titanium
Answer:
Granite and Titanium will sink
Explanation:
Granite and Titanium will sink in water.Granite and Titanium will sink in water because density of Granite and Titanium is higher then water. Also there raw shape does not help them to float on water.
What do we call the bond that forms when atoms share two pairs of electrons
(I have a test tomorrow and I'm doing a review right now but have no idea what the answer to this is.)
Please help ASAP 100 points points help I will mark you as brainlister
this is lithium ion with a +1 charge
What’s this called
Please ASAP
Answer:
carbon dioxide CO[tex]{2}[/tex]
Explanation:
Double Polar Covalent bonds with CO2
Explanation:
Keep in mind that CO2 is a nonpolar molecule
Your science teacher removed the gas from a birthday balloon. They discovered that the gas is made of the element helium. Inside that atom is:
A. A new substance
B. Protons, neutrons and electrons
C. A different element
D. All of the above
in the chemical equation HCI+CaCO3 which element cannot be apart of the products a carbon b chlorine c nitrogen d oxygen
Answer:
Nitrogen
Explanation:
The element nitrogen cannot be a product in the given reaction.
The reaction is;
HCl + CaCO₃
According to the law of conservation of matter, "matter is neither created nor destroyed in the cause of a chemical reaction".
The law suggests that, in a chemical reaction, we end up with the same species we started with. Although due to rearrangement of bonds, new compounds can form;
Starting atoms
H
Cl
Ca
O
These species will also be found in the product.
Name for each compoud
1.CO
2.H2SO4
3CaCO3
4 H202
5NaF
marine science flvs 2.03
can someone please send the answers for this!!!
Answer:
101
Explanation:
Answer:
Explanation:
How do I find the number of atoms using a chemical formula? ex: 4 HNO3
you should
MOL × NA(Avogadro Constant)
Mol = 4
HNO3 = 5 Atome ( 1H + 1N + 3O)
NA = 6.02 × 10* ( * = 23)
[tex]4 \times 5 \times 6.02 \times {10}^{23} = 20 \times 6.02 \times {10}^{23} = 120.4 \times {10}^{23}atom [/tex]
Answer:
2.408 x 10^24
GREETINGS!
One mole of a substance is equal to 6.02 × 10²³ units of that substance. The number 6.022 × 10²³ is known as Avogadro's number.
so if one mole of molecule is equal to that number so,
for 4 moles of [tex]HNO_{3}[/tex]= 4 x ([tex]6.02x10^{23}[/tex])
so answer is,
2.408 x 10^24
HOPE IT HELPS YOU.
Please help brainiest is award!
Answer: A.
Explanation:
The molecular formula for glucose is C6H12O6. This means that there are 6 carbon atoms, 12 hydrogen atoms, and 6 oxygen atoms bonded together to make one molecule of glucose.
Hopes this helps!
How many atoms are in this formula? 2Fe
Answer:
two
Explanation:
There are two atoms in 2 Fe, more correctly written as 2Fe or Fe2. Both atoms are from the same element, iron.
Answer:
2
Explanation:
There are two atoms of the same element in 2Fe.
Hope this helps! :)
Learning Task No. 2: Using the Periodic Table of Elements, determine the ele-
ments asked in each guide question. Write your answer in your notebook.
Guide Questions:
1. Which elements are likely to lose electrons?
2. Which elements are likely to ain electrons?
3. Which type of elements are likely to have no electrical charge at all?
Explanation:
1 metal they are likely to lose an electron
2non metals
3 Nobel gases because they are not reactive with stable valance number
Which of the following is NOT an example of a chemical change? *
O Corrosion
O Grinding
O Combustion
O Rust