Answer:
[tex]82[/tex]
Answer:
[tex]\boxed {\boxed {\sf 72 \ electrons}}[/tex]
Explanation:
Lead (Pb) has 82 protons, or positively charged particles. If this was a neutral atom of lead, then there would also be 82 electrons, or negatively charge particles to balance each other out and create an overall charge of 0.
However, we are given an ion of lead (Pb⁴⁺) which means the electrons and protons are not equal.
This is a 4+ ion. Since it is more positive, there must be fewer electrons than protons. In this case, it is 4 fewer electrons.
82 - 4= 78There must be 78 electrons.
How would life on Earth be different if its axis was not tilted with respect to its orbit?
All places would have the same climate.
There would be no seasons.
There would be no day and night.
The seasons would be much shorter.
IM IN A TEST
A solution of the acid contains hydrogen ions. Write an ionic equation for the reaction of sodium with the hydrogen ions in the acid. Include state symbols in your answer.
Answer:
The thing to recognize here is the fact that you're dealing with a neutralization reaction that features sodium hydroxide,
NaOH
, a strong base, and hydrochloric acid,
HCl
, a strong acid.
This tells you that the two reactants will dissociate completely in aqueous solution to produce cations and anions. More specifically, you will have
NaOH
(
a
q
)
→
Na
+
(
a
q
)
+
OH
−
(
a
q
)
HCl
(
a
q
)
→
H
+
(
a
q
)
+
Cl
−
(
a
q
)
Now, when these two solutions are mixed, the hydroxide anions produced by the strong base and the hydrogen ions produced by the strong acid will neutralize each other to produce water.
The sodium cations and the chloride anions act as spectator ions because they are present on both sides of the chemical equation as ions.
You can tell that this is the case because sodium chloride,
NaCl
, one of the two products of the reaction, is soluble in aqueous solution.
So, the complete ionic equation will be
H
+
(
a
q
)
+
Cl
−
(
a
q
)
+
Na
+
(
a
q
)
+
OH
−
(
a
q
)
→
Na
+
(
a
q
)
+
Cl
−
(
a
q
)
+
H
2
O
(
l
)
To get the net ionic equation, simply remove the spectator ions
H
+
(
a
q
)
+
Cl
−
(
a
q
)
+
Na
+
(
a
q
)
+
OH
−
(
a
q
)
→
Na
+
(
a
q
)
+
Cl
−
(
a
q
)
+
H
2
O
(
l
)
You will end up with
H
+
(
a
q
)
+
OH
−
(
a
q
)
→
H
2
O
(
l
)
SIDE NOTE You will sometimes see the hydrogen ion being replaced by the hydronium ion,
H
3
O
+
.
In this case, the dissociation of hydrochloric acid is represented by the chemical equation
HCl
(
a
q
)
+
H
2
O
(
l
)
→
H
3
O
+
(
a
q
)
+
Cl
−
(
a
q
)
The net ionic equation will now take the form
H
3
O
+
(
a
q
)
+
OH
−
(
a
q
)
→
2
H
2
O
(
l
)
the metallic compound reduced to the metal by electrolysis is _____
please girls answer, because I think u r always right.
Answer:
Explanation:
u wanted to talk
brain cells, blood cells, muscle cells
These cells are an example of:?
Answer:
Somatic Cells
Explanation:
Somatic cells are basically all bodily cells
Answer:
i don't know sorry
Explanation:
The law of conservation of energy states that
Answer:
Explanation:
The law of conservation of energy states that that energy can neither be created nor destroyed; rather, it can only be transformed or transferred from one form to another.
How many grams of barium sulfate, BaSO 4 , be precipitated when 2.25 moles of sodium sulfate , Na 2 SO 3 , reacts with an excess of barium chloride in solution ?
Answer:
525.1 g of BaSO₄ are produced.
Explanation:
The reaction of precipitation is:
Na₂SO₄ (aq) + BaCl₂ (aq) → BaSO₄ (s) ↓ + 2NaCl (aq)
Ratio is 1:1. So 1 mol of sodium sulfate can make precipitate 1 mol of barium sulfate.
The excersise determines that the excess is the BaCl₂.
After the reaction goes complete and, at 100 % yield reaction, 2.25 moles of BaSO₄ are produced.
We convert the moles to mass: 2.25 mol . 233.38 g/mol = 525.1 g
The precipitation's equilibrium is:
SO₄⁻² (aq) + Ba²⁺ (aq) ⇄ BaSO₄ (s) ↓ Kps
525.1 0 g of BaSO₄ are produced.
The reaction of precipitation is:
Na₂SO₄ (aq) + BaCl₂ (aq) → BaSO₄ (s) ↓ + 2NaCl (aq)
Ratio is 1:1. So 1 mol of sodium sulfate can make precipitate of 1 mol of barium sulfate.
Molar mass of [tex]BaSO_4[/tex] is 233.38 g/mol
The formula for the number of moles is as follows:-
[tex]Number\ of\ moles=\frac{Mass}{Molar\ Mass}[/tex]
[tex]Mass=2.25\ moles\times233.38\ g/mol\\=525.10\ g[/tex]
So, 525.10 g of barium sulfate be precipitated.
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What is the relationship between the density and position of each Earth layer?
Answer:
The atmosphere and Earth's interior are layered by density. Gravity pulls more strongly on denser materials so denser materials are at the center of things. Earth's core, at its center, is denser than its crust. The lowest layer of the atmosphere is denser than the upper layer.
Hope it helps
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THank you
Answer:
Gravity pulls more strongly on denser materials so denser materials are at the center of things.
Explanation:
Earths core at its center is denser than its crust the lowest layer of the atmosphere is denser than the upper layer
Magnesium, Cobalt, and Beryllium are all examples of
A. metals
C. metalloids
D. none of the above
B. nonmetals
How many molecules are there in 4372 grams of Na2SO4?
Answer: 30.7 moles
Explanation:
how is bacteria on mars counted as life but a heartbeat on earth is not?
Un móvil avanza con mru a razón de 25 m/s durante 2,54 h. Cuál es la distancia recorrida por el móvil
Answer:
La distancia recorrida por el móvil es 228.600 m
Explanation:
El movimiento rectilíneo uniforme MRU es el movimiento que describe un cuerpo o partícula a través de una línea recta a velocidad constante. Es decir:, en este caso el movimiento es lineal en una única dirección y la velocidad de desplazamiento es constante.
La velocidad es una magnitud física que expresa la relación entre el espacio recorrido por un objeto y el tiempo empleado para ello mediante la expresión:
[tex]velocidad=\frac{distancia}{tiempo}[/tex]
En este caso:
velocidad= 25 m/sdistancia= ?tiempo= 2,54 h= 9144 s (siendo 1 h= 3600 s)Reemplazando:
[tex]25 \frac{m}{s} =\frac{distancia}{9144 s}[/tex]
y resolviendo obtienes:
distancia= 25[tex]\frac{m}{s}[/tex] *9144 s
distancia= 228.600 m
La distancia recorrida por el móvil es 228.600 m
A movement is rectilinear uniform when an "object" (for example) travels in a straight path at a constant speed, given that its acceleration is zero.
To start solving an exercise, we obtain the data:Velocity (v) = 25m/s
Distance (d) = ?
Time (t) = 2.54hr = 9,144 s
Looking at the data, we see that the time is in hr, but we need it in seconds. Therefore we do a conversion from hours to minutes, taking into account that 1 hour is equal to 3600 seconds.
2,54 hr * (3600 sec / 1 h ) = 9144 secTo calculate the distance traveled by the mobile, the speed is multiplied by the time taken.
For this the following formula is applied:
d = v * tWe apply the data in the formula; to solve for the distance.
d = 25 m/s * 9144 sd = 228, 600 mAnswer: The distance traveled by the mobile is 228,600 meters.
A substance joined by this type of bond shares electrons
Answer: Covalent
Explanation:
A covalent compound is formed when an element shares its valence electron with another element. This compound is formed between two non metals. Example: [tex]HF[/tex]
An ionic compound is formed when an element completely transfers its valence electron to another element. The element which donates the electron is known as electropositive element or the metal and the element which accepts the electrons is known as electronegative element or non metal. Example: [tex]NaCl[/tex]
Why is light colour given off?
Answer:
Light is made up of wavelengths of light, and each wavelength is a particular colour. The colour we see is a result of which wavelengths are reflected back to our eyes. The visible spectrum showing the wavelengths of each of the component colours.
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can someone help me please-
i just need some answers-
Answer:
1.Newton's first law is often called the law of inertia.
2.Newton's second law of motion is F = ma
3.An object not wanting to change its speed or direction
4.a bike would have more acceleration
5.it doesn't have auto brakes and its lighter than a motorcycle
6. Second law
7. First law
8. First law
9. Second law
10. First law
Those should be right!
Chemical energy is contained in the chemical bonds of a substance. True or False
What conditions must be met for an object to be weightless?
in a lift if an object is moving with acceleration same as acc. due to gravity then apparent weight is 0. so it seems object is weightless.
or else I dunno maybe in space
technically you will be weightless when no force acts on you
What is a atmosphere
Given the following equation: CH4 + 202 CO2 + 2H2O
How many grams of CH4 are needed to react with 3.2 grams of O2?
Answer:
Mass = 0.8 g
Explanation:
Given data:
Mass of oxygen = 3.2 g
Mass of CH₄ = ?
Solution:
Chemical equation:
CH₄ + 2O₂ → CO₂ + 2H₂O
Number of moles of O₂:
Number of moles = mass/molar mass
Number of moles = 3.2 g/ 32 g/mol
Number of moles = 0.1 mol
Now we will compare the moles of CH₄ and O₂.
O₂ : CH₄
2 : 1
0.1 : 1/2 = 0.1 = 0.05
Mass of CH₄:
Mass = number of moles × molar mass
Mass = 0.05 mol × 16 g/mol
Mass = 0.8 g
Answer:
0.8
Explanation:
Chunga
A satellite and a hockey puck are alike because they illustrate Newton's first law of motion.
True
False
Answer:
It would be True
Explanation:
Because they both have the same push of gravity. Gravity affects all objects equally. If you drop an egg and a watermelon at the same time they would both collide with the floor at the same time.
HELP URGENT!! IN CHEMISTRY MOLARITY IS THE TOPIC
Answer:
i think 3 is the answer cuz i search it up
NEED ASAP. WILL MARK BRAINLIEST!
1. (06.01 LC)
Based on the kinetic theory, which statement is true? (15 points)
A. The particles of matter are stationary.
B. Matter is composed of very small particles.
C. Matter is made up of only charged particles.
D. The particles of matter have zero kinetic energy.
Answer:
B. Matter is composed of very small particles.
Explanation:
All matter is composed of extremely small particles called atoms. All atoms of a given element are identical in size, mass,
The statement is true based on the kinetic theory is that; "matter is composed of very small particles.".
Kinetic theory of matter
The kinetic theory of matter holds that the particles that compose matter are in constant random motion. In this theory, all matter is composed of molecules.
Now, the statement is true based on the kinetic theory is that; "matter is composed of very small particles.".
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What astronomical event correspond to the passage of one month
Answer:
It takes approximately 28 days for the Moon to revolve around Earth. Revolution is the elliptical motion of a body traveling around another body
Explanation:
An atom of helium is smaller in width then an atom of hydrogen, but it's more then twice the mass. Why are these different?
Answer:
i think it cuz ones broken down by fision more
Explanation:
Balance this equation. Not all spots have to have a number.
____Na(s) + ____H2O(g) → ____NaOH(s) + ____H2 (g)
2Na+2H2O----2NaOH+H2
• Compare the transmutations caused by positron emissions and electron capture
Positron emission gives a new nucleus with the same mass number but an atomic number that is one less than the old one. Electron emission gives an atomic number that is one greater. Both positrons and electrons are β particles. A positron is the antimatter counterpart of an electron
For the equation SnO2 + 2H2 Sn + 2H2O, tin (IV) oxide reacts with excess hydrogen to produce tin and water. What is the limiting reactant?
A) SnO2
B) H2
C) Sn
D) H2O
Answer:
SnO2
Explanation:
The limiting reactant is the reactant that runs out first during a chemical reaction.
Reactants are on the left side of the reaction, so SnO2 and H2. They tell us in the question that there is "excess" hydrogen (H2), so we know there is plenty of it, as "excess" means "more than enough." If we have more than enough hydrogen, then we know that we will run out of SnO2 first.
:)
Answer:SnO2
Explanation:
What does it mean if a trait is inherited
Answer:
An inherited trait is one that is genetically determined. Inherited traits are passed from parent to offspring according to the rules of Mendelian genetics.
Explanation:
6 Which element requires the least amount of
energy to remove the most loosely held electron
from a gaseous atom in the ground state?
(1) Na
(3) P
(2) Ar
(4) Ci
Answer: 1) Na because it requires least amount of energy.
Na requires the least amount of energy to remove the most loosely held electron.
Why does Na have the least ionization enthalpy among the given elements?Electronic configuration of the elements:Na - [Ne] 3s¹
P - [Ne] 3s² 3p³
Ar - [Ne] 3s² 3p⁶
Cl - [Ne] 3s² 3p⁵
As it can be seen, Na after losing one electron from its outermost subshell attains a stable noble gas configuration. So, it will require a very less amount of energy i.e., ionization enthalpy, to remove that electron.P, which already has a half-filled subshell, will not readily lose the electrons and hence requires more amount of energy.Ar has the noble gas configuration i.e., all its subshells are fully filled. A very large amount of energy will be required to remove its electron.Learn more about ionization energy here:
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what is the meaning of a mixture
Answer:
a substance made by mixing other substances together.
4 Elliot has some stearic acid. It is in the solid state.
a Describe how Elliot could use the apparatus below to measure the melting point of his
stearic acid.
Answer:
it is in solid state
Explanation:
at 100% heat
At regular intervals, check the stearic acid's temperature. Make a note of the findings and create a temperature vs time graph.
What is Temperature?The physical concept of temperature indicates in numerical form how hot or cold something is. A thermometer is used to determine temperature. Thermometers are calibrated using a variety of temperature scales, which historically defined distinct reference points and thermometric substances.
For above given example, check the temperature of the stearic acid often and make a note of the results and plot the temperature against time.
Temperature is not the same as the energy of a thermodynamic system; for instance, an iceberg has a significantly larger total heat energy than a match, despite the fact that a match is burning at a much higher temperature.
Thus, at regular intervals, check the stearic acid's temperature. Make a note of the findings and create a temperature vs time graph.
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