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3 years ago

The proton,neutron and electrons in the atom of the element represented by the symbol 231Y89 are:

Chemistry

1 answer:

Simora [160]3 years ago

3 0

Answer:

Protons = 89

Neutrons = 142

Electrons = 89

Option C

Explanation:

Hello,

Were required to find the proton, neutron and electron of an element Y

The atomic mass of element Y is composed of the protons and neutrons while the atomic number is the exact amount of protons present in the element.

Element = ₈₉²³¹Y

Atomic number = 89

Number of protons = 89

Number of electrons = 89

Atomic mass = 231

Atomic mass = protons + neutrons

231 = 89 + neutrons

Neutrons = 231 - 89

Neutrons = 142

Therefore the number of protons is 89, number of neutrons is 142 and number of electrons is 89.

Note: for an electrically neutral atom, the number of protons must be equal to the number of electrons

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The reaction a(g)⇌b(g) has an equilibrium constant of 5.8 and under certain conditions has q = 336. part a what can you conclude

Vika [28.1K]

Answer:

The answer is "As $Q=336$ , at high-temperature $\Delta G_{rxn}>0$ and When $K>1,$ $\Delta G^{\circ}_{rxn}>0$ ."

Explanation:

The equation for the reaction is:

$A(g) \leftrightharpoons B(g)$

$K=5.8\\\\Q=336$

At equilibrium,

$\Delta G^{\circ}_{rxn}>0$ $=-RT \ln \ K$

When k=5.8(>1), the value of $\ln k$ would be positive

So, $\Delta G^{\circ}_{rxn}$ is negative (< 0)

So if K > l, $\Delta G^{\circ}_{rxn}$

If the reaction is not in equilibrium so the equation is :

$\Delta G_{rxn}>0$ = $\Delta G^{\circ}_{rxn}$ $+RT \ln Q$

Substituting the expression:

$\Delta G_{rxn}>0$ $= (-RT \ln K) + RT \ln Q$

$= RT(\ln Q- \ln K)\\= RT(\ln (336)-\ln (5.8))\\= RT(4.06)$

It is the positive value for all temperatures.

So, As Q = 336, at the high temperature $\Delta G_{rxn}>0$ .

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3 years ago

The element lead (pb) consists of four naturally occurring isotopes with atomic masses 203.97302,205.97444,206.97587, n 207.9766

Marina CMI [18]

The method of determining the most common isotope of lead is by determining the average atomic mass. The formula for determining the average atomic mass is:

$average atomic mass = \Sigma {percent abundance}\times {atomic mass}$

Substituting the values in the formula:

$average atomic mass = \frac{{203.97302}\times {1.4}+{205.9744}\times {24.1}+{206.97587}\times {22.1}+{207.97663}\times {52.4}}{100}$

$average atomic mass = \frac{285.562228+4963.984004+4574.166727+10897.975412}{100}$

$average atomic mass = \frac{20721.688371}{100} = 207.22 amu$

The most common isotope of lead is:

Lead - 207.22 amu

The atomic symbol of lead is $Pb$ . The atomic number of $Pb$ is 82.

So, the the most common isotope of lead can be written as:

$_{207.22}^{82}Pb$ and Lead - 207.22 amu.

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3 years ago

87 g of oxygen gas would occupy how many liters of volume at stp

loris [4]

Number of mole : mass/ molar mass

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volume = number of mole x molar volume
volume = 2.719 x 22.4
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Answer:

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2 years ago

Why would "not flammable" be a chemical property rather than a physical property ?

Dmitrij [34]

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