Answer:
Calcium
Explanation:
Calcium is the only metal here
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A positive ion is an atom or a molecule that has a net positive charge. The charge of the proton in an atom or a molecule is positive.
A subatomic found in the atom or the molecule that lacks a positive charge is called an electron.
The correct answer is:
Option C. Calcium
This can be explained by:
Compounds or substances which have positive ions engaged in a sea of movable electrons are assumed to be metals.The electrons existing in the metals encompass the positively loaded nuclei instead of projecting their assigned atoms.Calcium is the only metal found in the given list and hence is the answer.
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Describe the life cycle of a star what determines the path a star could take.
What's the equation for the reaction of Trifluoro bromide with Ammonia gas. ( brainliest assured )
Answer:
Ammonium bromide can be prepared by the direct action of hydrogen bromide on ammonia. It can also be prepared by the reaction of ammonia with iron(II) bromide or iron(III) bromide, which may be obtained by passing aqueous bromine solution over iron filings.
Explanation:
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A line in the Balmer series of the emission spectrum of atomic hydrogen is observed at a wavelength of 486.3 nm. Deduce the upper state principal quantum number for this transition.
Answer:
4
Explanation:
The Balmer series refers to to a series of spectral emission lines of the hydrogen atom that occurs when an electron moves from higher energy levels to the energy level of n= 2.
Hence;
λ = 486.3 * 10^-9 m
RH = 1.097 * 10^7 m-1
nf = 2
ni = ?
Using the formula;
1/λ = RH (1/nf^2 - 1/ni^2)
1/486.3 * 10^-9 = 1.097 * 10^7 (1/4 - 1/ni^2)
2.06 * 10^6/1.097 * 10^7 = (1/4 - 1/ni^2)
0.188 = 1/4 - 1/ni^2
1/ni^2 = 1/4 - 0.188
1/ni^2 = 0.25 - 0.188
1/ni^2 = 0.062
ni^2 = 16
ni = 4
) The volume of a balloon was 50,200 litres. If the temperature
at ground level was 25 degree celcius and the atmospheric pressure was
720mm Hg. How many moles of Hydrogen gas were needed to
fill the balloon?
Answer:
1943.1 moles
Explanation:
From the question given above, the following data were obtained:
Volume (V) = 50200 L
Temperature (T) = 25 °C
Pressure (P) = 720 mmHg
Number of mole (n) of H₂ =?
Next, we shall convert 25 °C to Kelvin temperature. This can be obtained as follow:
T(K) = T(°C) + 273
Temperature (T) = 25 °C
Temperature (T) = 25 °C + 273
Temperature (T) = 298 K
Next, we shall convert 720 mmHg to atm. This can be obtained as follow:
760 mmHg = 1 atm
Therefore,
720 mmHg = 720 mmHg × 1 atm / 760 mmHg
720 mmHg = 0.947 atm
Thus, 720 mmHg is equivalent to 0.947 atm
Finally, we shall determine number of mole of Hydrogen gas, H₂, needed to fill the balloon as follow:
Volume (V) = 50200 L
Temperature (T) = 298 K
Pressure (P) = 0.947 atm
Gas constant (R) = 0.0821 atm.L/Kmol
Number of mole (n) of H₂ =?
PV = nRT
0.947 × 50200 = n × 0.0821 × 298
47539.4 = n × 24.4658
Divide both side by 24.4658
n = 47539.4 / 24.4658
n = 1943.1 moles
The Goodyear blimp contains 5.7 x 10^6 L of helium at 25 degrees Celsius and 1 atm. What is the mass in grams of the helium inside the blimp
Answer:
1.72x10⁻⁵ g
Explanation:
To solve this problem we use the PV=nRT equation, where:
P = 1 atmV = 5.7x10⁶ Ln = ?R = 0.082 atm·L·mol⁻¹·K⁻¹T = 25 °C ⇒ (25+273.16) = 298.16 KAnd we solve for n:
1 atm * 5.7x10⁶ L = n * 0.082 atm·L·mol⁻¹·K⁻¹ * 298.16 K n = 4.29x10⁻⁶ molFinally we convert moles of helium to grams, using its molar mass:
4.29x10⁻⁶ mol * 4 g/mol = 1.72x10⁻⁵ gPLEASE HELP
What do you know about valence electrons?
Answer:
Valence electrons are the electrons in the outermost shell, or energy level, of an atom
Explanation:
Answer:
Valence electrons are the electrons in the outermost shell, or energy level, of an atom. For example, oxygen has six valence electrons, two in the 2s subshell and four in the 2p subshell. We can write the configuration of oxygen's valence electrons as 2s²2p⁴
In the equation:
X →
226
88
Ra + He
The symbol Xrepresents
A)
222
Th
86
222
B)
Rn
86
230 Th
C)
90
D)
230
90
Rn
Answer:
²³⁰₉₀Th
Explanation:
X → ²²⁶₈₈Ra + ⁴₂He
The given equation shows the alpha emission. When He particle emit the original atom convert into the atom having mass number less than 4 and atomic number less than 2 as compared to parent atom the starting atom. It means the parent atom is ²³⁰₉₀Th.
Alpha radiations are emitted as a result of radioactive decay. The atom emit the alpha particles consist of two proton and two neutrons. Which is also called helium nuclei. When atom undergoes the alpha emission the original atom convert into the atom having mass number less than 4 and atomic number less than 2 as compared to parent atom the starting atom.
Alpha radiations can travel in a short distance.
These radiations can not penetrate into the skin or clothes.
These radiations can be harmful for the human if these are inhaled.
These radiations can be stopped by a piece of paper.
₉₂U²³⁸ → ₉₀Th²³⁴ + ₂He⁴ + energy
Definition in your own words
Will check if you got it from online.
Word: States (Phases) of Matter
Answer:
Liquid,gas,solid and plasma
Explanation:
There four phases of matter. These phases are the gas phase(steam), the liquid phase(water), the solid phase(Ice) and finally the plasma phase(moucous).
In the nucleus, a sodium atom (Na) has 11p+ and 12 nºo. How would you write the
sodium ion based on the loss of one electron?
Answer:
Na⁺
Explanation:
Given parameters:
Number of protons = 11
Number of neutrons = 12
Writing the expression based on sodium ion that lost one electron;
In a neutral sodium atom, the number of protons and electrons are the same. Number of protons are the the positively charged particles in an atom.
Number of electrons are the negatively charged particles.
If an atom loses electron for instance sodium:
Number of electrons = 10
Number of protons = 11
Charge on the atom = 11 - 10 = 1+
So, the symbol of the atom is Na⁺
what is the meaning of science
Answer:
Here goes
Explanation:
the intellectual and practical activity encompassing the systematic study of the structure and behaviour of the physical and natural world through observation and experiment.
What is the first step for response to an emergency situation?
Answer:
Back away from the situation and tell the supervisor/teacher
The density of whole milk 1.04 g per mL. What is the volume (in quarts) of 18.5 pounds of whole milk?
The volume : 8,526 quarts
Further explanationGiven
The density of whole milk = 1.04 g/ml
mass = 18.5 pounds
Required
The volume
Solution
Conversion of mass
1 pound = 453,592 g
18.5 pounds = 8391,45 g
Density formula:
[tex]\large{\boxed {\bold {\rho~=~ \frac {m} {V}}}}[/tex].
Input the value :
V = m : ρ
V = 8391,45 g : 1.04 g/ml
V = 8068.7 ml
1 ml = 0,00105669 quarts
8068.7 ml =8,526 quarts
What fraction of a 100 g sample of K - 42 will remain after 24.8 hours?
Answer:
1/4
Explanation:
From the question given above, the following data were:
Original amount (N₀) = 100 g
Time (t) = 24.8 h
Fraction remaining =?
NOTE: The half-life of K–42 is 12.4 h
Next, we shall determine the number of half-lives that has elapse. This can be obtained as follow:
Time (t) = 24.8 h
Half-life (t½) = 12.4 h
Number of half-lives (n) =?
n = t / t½
n = 24.8 / 12.4
n = 2
Finally, we shall determine the fraction remaining. This can be obtained as follow:
Number of half-lives (n) = 2
Fraction remaining =?
Fraction remaining = 1/2ⁿ
Fraction remaining = 1/2²
Fraction remaining = 1/4
PLEASE HELP with these problems ASAP!!! 30 points!!
Answer:
which?........................
How many moles are in 17.0 grams of H2O2?
Answer: 0.500
Explanation:17.0 g H202 x (1 mol H202/34.0 g H202)=0.500 mol H202
Answer: 0.5 moles are present in 17.0 g of [tex]H_{2}O_{2}[/tex] .
Explanation:
Number of moles present in a substance is the given mass divided by molar mass of the substance.
As the given mass of [tex]H_{2}O_{2}[/tex] is 17.0 g and its molar mass is 34 g/mol.
Hence, number of moles present in given 17.0 g of [tex]H_{2}O_{2}[/tex] is as follows.
No. of moles = [tex]\frac{mass}{molar mass}[/tex]
= [tex]\frac{17.0 g}{34 g/mol}[/tex]
= 0.5 moles
Therefore, 0.5 moles are present in 17.0 g of [tex]H_{2}O_{2}[/tex] .
What are the three states in which water exists on Earth?
consider the following intermediate reactions. the overall chemical reaction is as follows. what is the correct enthalpy diagram using the hess law for this system
The question is incomplete, here is the complete question:
Consider the following intermediate reactions.
[tex]CH_4(g)+2O_2\rightarrow CO_2(g)+2H_2O(g);\Delta H_1=-802kJ[/tex]
The overall chemical reaction is as follows:
[tex]CH_4(g)+2O_2(g)\rightarrow CO_2(g)+2H_2O(I);\Delta H_{rxn}=-890kJ[/tex]
What is the correct enthalpy diagram using the Hess law for this system? (Image is attached below)
Answer: The correct image is Image A.
Explanation:
According to Hess’s law of constant heat summation, the amount of heat absorbed or evolved in a given chemical equation or system remains the same whether the process occurs in one step or in several steps.
According to this law, the enthalpies of these chemical equation can be treated as ordinary algebraic expression and can be added or subtracted to know the required equation.
It also means that the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.
The given intermediate reactions are:
[tex]CH_4(g)+2O_2(g)\rightarrow CO_2(g)+2H_2O(l);\Delta H_1=-802kJ[/tex] ...(1)
[tex]2H_2O(g)\rightarrow 2H_2O(l);\Delta H_2=-88kJ[/tex] ....(2)
The final reaction follows:
[tex]CH_4(g)+2O_2(g)\rightarrow CO_2(g)+2H_2O(l);\Delta H_{rxn}=-890kJ[/tex]
Negative sign of the enthalpy represents the heat is being released which is represented by the downward arrow in the diagram.
By adding equation 1 and equation 2, we get:
[tex]\Delta H_{rxn}=\Delta H_1+\Delta H_2\\\\\Delta H_{rxn}=-802+(-88)=-890kJ[/tex]
Hence, the correct image is image A.
Answer:
A
Explanation:
Edg
Which planet has these characteristics?
- cold at the surface, hot at the core
- 30 moons orbiting it
- the largest rings
- a surface that is not solid
Pluto
Jupiter
Neptune
Saturn
Compare the patterns of earthquakes, volcanoes, and mountain ranges on earth?
At diverging plate boundaries, earthquakes occurs as the plates pull away from each other. Volcanoes form between the plates, as magma rises upward from the underlying mantle. Second, two plates may come together, at a converging plate boundary. Two situations are possible at converging plate boundaries.
Mountain ranges, volcanoes, and earthquakes can all be found when convergent borders occur. Finally, transform boundary locations are also the site of earthquakes. Every learning exercise we completed served as a piece of proof.
What is earthquakes ?When two chunks of the ground abruptly slide past one another, an earthquake results. The fault or fault plane is the area where they slide.
Earthquakes often result from subsurface rock breaking unexpectedly and fast movement along a fault. The seismic waves that cause the ground to tremble are brought on by this quick release of energy.
A fault line causes the Earth's crust to suddenly shift, causing an earthquake. The epicenter is the place where an earthquake first occurs. Near the epicenter of an earthquake, shaking may be quite violent.
Thus, mountain ranges, volcanoes, and earthquakes can all be found when convergent borders occur.
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A solid reactant is placed into a beaker of a warm water. The liquid vigorously bubbles as the solid dissolves into the solution. What will most likely happen if the temperature of the liquid is slightly reduced?
Answer:
Fewer bubbles will be produced because of fewer collisions of reactant molecules
Explanation:
As the solid dissolves into the solution after the liquid has been vigorously bubbled, if the temperature of the liquid is reduced a little, what will happen is that fewer bubbles will be produced as a result of lesser amount of collisions occurring between the reactant molecules
Answer:
b
Explanation:
Which of the following describes a perpetual-motion machine?
A. A battery that contains one oxidized metal and one reduced metal
B. A renewable energy source
C. A motor that requires no energy input once it is running
D. An electric motor that is powered by an electromagnet
SUBMIT
Answer:
a motor that requires no energy input once it is running
Answer:
c
Explanation:
a p e x :)
Is Na2SO4 ionic or covalent
Answer: What types of bonds exist between the atoms in a molecule of sodium sulfate, Na2SO4 ? The formula for this compound can be written as [Na+]2[SO42-], the sulfate anion is formed by covalent bonding between sulfur and oxygen. Since there is a bond polarity to a S-O bond these are polar covalent bonds.
Explanation:
The sulphate anion is created via covalent interaction between oxygen and sulphur, and the formula to this chemical is [[tex]Na^+[/tex]][[tex]SO_4^{2-}[/tex]]. These S-O bonds constitute polar covalent bonds because they have a bond polarity.
A polar bond represents a particular type of covalent bond in general. It is also the point at which an ionic bond and an unadulterated covalent bond begin to form, according to another definition. A polar covalent bond, on the other hand, is a link that occurs between two atoms and is made up of electrons which are scattered unevenly if we would like to explain it more precisely. The molecules have a tendency to have an electrical dipole moment in which the two ends are slightly either positive or negative as a result of this condition. The sulphate anion is created via covalent interaction between oxygen and sulphur, and the formula to this chemical is [[tex]Na^+[/tex]][[tex]SO_4^{2-}[/tex]]. These S-O bonds constitute polar covalent bonds because they have a bond polarity.
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The density of water at 4 degrees Celsius is 1.000 g/mg is it chemical or physical property?
Answer:
Physical Property
Explanation:
Density, mass, volume, color, melting and boiling points, etc. are all physical properties. No matter what changes, the chemical makeup stays the same.
Flamability, acidity, toxicity, etc. are chemical properties, because they chemically change the makeup of the object/thing.
When relative humidity is at 100 percent, air is said to be what?
Answer:
Fully saturated or "a chance of rain"
Explanation:
When relative humidity reaches 100%, the air is fully saturated with vapor. That means that there is a possibility of rain.