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3 years ago

________ is the force that keeps planets in orbit around the sun

Chemistry

2 answers:

Sphinxa [80]3 years ago

7 0

Answer: Gravity
gravity pulls down anything that is not held up by some other force

SpyIntel [72]3 years ago

6 0

Answer:

GrAvItY

Explanation:

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What is the most highly populated rotational level of Cl2 (i) 25deg C and (ii) 100 deg C? Take B=0.244cm-1.This question should

horsena [70]

Answer:

$J_{m} = 20$

$J_{m} = 22.5$

Explanation:

From the question we are told that

The first temperatures is $T_1 = 25^oC = 25 +273 =298 \ K$

The second temperature is $T_2 = 100^oC = 100 +273 = 373 \ K$

Generally the equation for the most highly populated rotational energy level is mathematically represented as

$J_{m} = [ \frac{RT}{2B}] ^{\frac{1}{2} } - \frac{1}{2}$

Here R is the gas constant with value $R =8.314 \ J\cdot K^{-1} \cdot mol^{-1}$

Also

B is given as $B=\ 0.244 \ cm^{-1}$

Generally the energy require per mole to move 1 cm is 12 J /mole

So $0.244 \ cm^{-1}$ will require x J/mole

$x = 0.244 * 12$

=> $x = 2.928 \ J/mol$

So at the first temperature

$J_{m} = [ \frac{8.314 * 298 }{2* 2.928 }] ^{\frac{1}{2} } - 0.5$

=> $J_{m} = 20$

So at the second temperature

$J_{m} = [ \frac{8.314 * 373 }{2* 2.928 }] ^{\frac{1}{2} } - 0.5$

=> $J_{m} = 22.5$

3 0

3 years ago

PLEASE HELP WILL AMRK BRAINLIEST<br> what is the atomic mass of Na3PO4?

Ira Lisetskai [31]

Answer:

163.94

Explanation:

Na = 22.99 (3)

P = 30.97

O = 16.00 (4)

22.99(3) + 30.97 +16.00(4) = 163.94

Hope that helps

4 0

2 years ago

Read 2 more answers

The enthalpy change for the reaction of titanium metal with gaseous iodine is given by the following thermochemical equation: 2

julia-pushkina [17]

Answer : The enthalpy change for the reaction is, 419.5 kJ

Explanation :

According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.

The given chemical reaction is,

$2Ti(s)+3I_2(g)\rightarrow 2TiI_3(s)$ $\Delta H=-839kJ$

Now we have to determine the enthalpy change for the reaction below:

$TiI_3(s)\rightarrow Ti(s)+\frac{3}{2}I_2(g)$ $\Delta H'=?$

By reversing and then dividing the reaction by 2, we get the enthalpy change for the reaction.

The expression will be:

$\Delta H'=-\frac{(\Delta H)}{2}$

$\Delta H'=-\frac{(-839kJ)}{2}$

$\Delta H'=419.5kJ$

Therefore, the enthalpy change for the reaction is, 419.5 kJ

3 0

3 years ago

If a dog has a mass of 21.5kg, what is his mass in the following units?

PolarNik [594]

Answer: 21.5kg in grams is 21,500 grams

21.5kg in mg is 215,000,00

Explanation:

5 0

4 years ago

A field worker is exposed to a xylene for a duration of 8 weeks at 40 hrs/wk. The concentration of xylene in the workplace is 40

Andrej [43]

Answer:

The chronic daily intake during the period of exposure is most nearly 0.012 mg/kg day.

Explanation:

Number of hours worker exposed to xylene = $40 hr/week\times 8 week = 320 hours$

The concentration of xylene in the workplace = $40 \mu g/m^3$

The worker is inhaling air at a rate of $0.9 m^3/hr$ .

Amount xylene inhaled by worker in an hour :

= $40\mu g/m^3\times 0.9 m^3/hr=36 \mu g/hr$

Amount xylene inhaled by worker in 320 hours:

$36 \mu g/hr\times 320 hr=11,520 \mu g=11,520\times 0.001 mg=11.520 mg$

1 μg = 0.001 mg

Amount xylene inhaled by worker in 320 hours = 11.520 mg

1 day = 24 hours

Amount xylene inhaled by worker in 1 day:

$\frac{24}{320}\times 11.520 mg=0.864 mg$

Assuming 70 kg body mass, the chronic daily intake of xylene :

$\frac{0.864 mg/day}{70 kg}=0.01234 mg/ kg day\approx 0.012 mg/ kg day$

The chronic daily intake during the period of exposure is most nearly 0.012 mg/kg day.

5 0

3 years ago