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3 years ago

HURRY This scientist proposed that atoms have a nucleus. Thomson

1 answer:

4 0

it was earnest rutherford he did the gold foil experiment where he shot alpha particles at gold foil that was supposed to be about 1 atom thick. He expected all the atoms to pass straight through but some bounced back, so he proposed that there was something small dense and positive in atoms aka the nucleus

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There are always attractive forces between a collection of atoms or molecules which may not be negligible as suggested by the ki

Harrizon [31]

Answer:

Negligible

Explanation:

According to the kinetic theory of gases, the degree of intermolecular interaction between gases is minimal and gas molecules tend to spread out and fill up the volume of the container.

If the attraction between gas molecules increases, then the volume of the gas decreases accordingly. This is because, gas molecules become highly attracted to each other.

This intermolecular attractive force may be so strong, such that the actual volume of the gas become negligible compared to the volume of the container.

7 0

3 years ago

Consider the reaction. 2 Pb ( s ) + O 2 ( g ) ⟶ 2 PbO ( s ) An excess of oxygen reacts with 451.4 g of lead, forming 367.5 g of

Art [367]

Answer : The percent yield of the reaction is, 75.6 %

Solution : Given,

Mass of Pb = 451.4 g

Molar mass of Pb = 207 g/mole

Molar mass of PbO = 223 g/mole

First we have to calculate the moles of Pb.

$\text{ Moles of }Pb=\frac{\text{ Mass of }Pb}{\text{ Molar mass of }Pb}=\frac{451.4g}{207g/mole}=2.18moles$

Now we have to calculate the moles of $PbO$

The balanced chemical reaction is,

$2Pb(s)+O_2(g)\rightarrow 2PbO(s)$

From the reaction, we conclude that

As, 2 mole of $Pb$ react to give 2 mole of $PbO$

So, 2.18 mole of $Pb$ react to give 2.18 mole of $PbO$

Now we have to calculate the mass of $PbO$

$\text{ Mass of }PbO=\text{ Moles of }PbO\times \text{ Molar mass of }PbO$

$\text{ Mass of }PbO=(2.18moles)\times (223g/mole)=486.1g$

Theoretical yield of $PbO$ = 486.1 g

Experimental yield of $PbO$ = 367.5 g

Now we have to calculate the percent yield of the reaction.

$\% \text{ yield of the reaction}=\frac{\text{ Experimental yield of }PbO}{\text{ Theoretical yield of }PbO}\times 100$

$\% \text{ yield of the reaction}=\frac{367.5g}{486.1g}\times 100=75.6\%$

Therefore, the percent yield of the reaction is, 75.6 %

3 0

3 years ago

Examples of pure and impure substances

erastova [34]

Pure- table salt
Impure- vegetable oil

8 0

3 years ago

Read 2 more answers

A rectangular block of solid carbon (graphite) floats at the interface of two immiscible liquids.

Sergio039 [100]

Explanation:

Let us take the volume of block is x.

Since, the block is floating this means that it is in equilibrium. Formula to calculate net force will be as follows.

$F_{net} = Buoyancy force(F_{b}) - weight force(w)$

Also, buoyancy force $(F_{b})$ = (volume submerged in water × density of water) + (volume in oil × density of oil)

$(F_{b})$ = $(0.592 V \times \rho) + (1 - 0.592)V \times 1000 g$

= $(0.592 V \times \rho + 408 V)$ g

As, W = V × density of graphite × g

It is given that density of graphite is $2.16 g/cm^{3}$ or 2160 $kg/m^{3}$ .

So, W = 2160 V g

$F_{net}$ = (0.592 V \rho + 408 V) g - 2160 V g = 0

$0.592 \rho$ = 1752

$\rho$ = 2959.46 $kg/m^{3}$ or 2.959 $g/cm^{3}$ is the density of oil.

It is given that mass of flask is 124.8 g.

Mass of 35.3 $cm^{3}$ oil = $35.3 \times 2.959$ 104.7 g

Hence, in second weighing total mass will be calculated as follows.

(124.8 + 104.7) g

= 229.27 g

Thus, we can conclude that in the second weighing mass is 229.27 g.

5 0

3 years ago

According to naming rules, the types of compound that use prefixes in their names are ________.

arlik [135]

Answer:

Covalent compounds.

Explanation:

Hello,

In this case, when forming chemical bonds in order to form compounds, we say that if electrons are shared, covalent compounds are to be formed and they usually have subscripts that need prefixes to be named, for instance phosphorous pentachloride (PCl5), dichlorine heptoxide (Cl2O7), carbon tetrachloride (CCl4) and many others.

Regards.

6 0

3 years ago