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3 years ago

How many naturally occurring elements are there

Chemistry

1 answer:

arlik [135]3 years ago

4 0

Answer: Out of 118 elements, 94 occur naturally

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What does geotropism enable plants to do

LUCKY_DIMON [66]

Answer:

Growing toward gravity is called geotropism. Plants also exhibit phototropism, or growing toward a light source. This response is controlled by a plant growth hormone called auxin. As shown in Figure below, auxin stimulates cells on the dark side of a plant to grow longer.

Explanation:

Hope this helps and have a great day :)

6 0

3 years ago

If 33.9 ml of h3po4 neutralizes 23.4 ml of 2.28 m koh, what is the molarity of the phosphoric acid?

SpyIntel [72]

Answer: 1.57 M

Explanation:

$M_{A}V_{A}=M_{B}V_{B}\\(33.9)M_{A}-=(23.4)(2.28)\\M_{A}=\frac{(23.4)(2.28)}{33.9}=\boxed{1.57 \text{ M}}$

7 0

2 years ago

a glass container was initially charged with 1.50 mol of a gas sample at 3.75 atm and 21.7C. some of the gas was release as the

butalik [34]

Answer:

0.39 mol

Explanation:

Considering the ideal gas equation as:

$PV=nRT$

where,

P is the pressure

V is the volume

n is the number of moles

T is the temperature

R is Gas constant having value = 0.0821 L.atm/K.mol

At same volume, for two situations, the above equation can be written as:-

$\frac {{n_1}\times {T_1}}{P_1}=\frac {{n_2}\times {T_2}}{P_2}$

Given ,

n₁ = 1.50 mol

n₂ = ?

P₁ = 3.75 atm

P₂ = 0.998 atm

T₁ = 21.7 ºC

T₂ = 28.1 ºC

The conversion of T( °C) to T(K) is shown below:

T(K) = T( °C) + 273.15

So,

T₁ = (21.7 + 273.15) K = 294.85 K

T₂ = (28.1 + 273.15) K = 301.25 K

Using above equation as:

$\frac{{n_1}\times {T_1}}{P_1}=\frac{{n_2}\times {T_2}}{P_2}$

$\frac{{1.50\ mol}\times {294.85\ K }}{3.75\ atm}=\frac{{n_2}\times {301.25\ K }}{0.998\ atm}$

$n_2=\frac{{1.50}\times {294.85}\times 0.998}{3.75\times 301.25}\ mol$

Solving for n₂ , we get:

n₂ = 0.39 mol

7 0

3 years ago

A sodium ion, Na+, with a charge of 1.6×10−19C and a chloride ion, Cl− , with charge of −1.6×10−19C, are separated by a distance

sasho [114]

Answer:

$W\geq 2.1x10^{-19}J$

Explanation:

Due to Coulomb´s law electric force can be described by the formula $F=K\frac{q_{1}.q_{2}}{r^{2}}$ , where K is the Coulomb´s constant ( $9x10^{9} N\frac{m^{2} }{C^{2} }$ ), $q_{1}$ = Charge 1 (Na+ in this case), $q_{2}$ is the charge 2 (Cl-) and r is the distance between both charges.

Work made by a force is W=F.d and total work produced is the change in energy between final and initial state. this is $W=W_{f} -W_{i}$ .

so we have $W=W_{f} -W_{i} =(K\frac{q_{(Na+)}q_{(Cl-)}rf}{r_{f} ^{2}})-(K\frac{q_{(Na+)}q_{(Cl-)}ri}{r_{i} ^{2}})=Kq_{(Na+)}q_{(Cl-)[\frac{1}{{r_{f}}} -\frac{1}{{r_{i}}}]$

Given that ri= 1.1nm= $1.1x10^{-9}m$ and rf= infinite distance

$W=(9x10^{9})(1.6x10^{-19})(-1.6x10^{-19})[\frac{1}{\alpha }-\frac{1}{(1.1x10^{-9})}]=2.1x10^{-19}J$

6 0

3 years ago

Which one is not a form of energy?

yuradex [85]

Please add you assignment.

6 0

3 years ago