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3 years ago

Yvus UVILLE auuuulll

Chemistry

2 answers:

vfiekz [6]3 years ago

5 0

Answer:

The 20 kg stone traveling at 10m/s

Explanation:

Hi, the kinetic energy is the energy available of the objects in movement.

That energy can be calculated be the next formula:

$ec=0.5*m*v^2$

Where:

ec is the kinetic energy [J]
m is the mass of the object [kg]
v is the velocity of the object [m/s]

Case A:

$ec=0.5*20kg*(10m/s)^2$

$ec=1000 J$

Case B:

$ec=0.5*40kg*(4m/s)^2$

$ec=320 J$

Case C:

$ec=0.5*30kg*(6m/s)^2$

$ec=540 J$

Case D:

$ec=0.5*50kg*(2m/s)^2$

$ec=100 J$

sveta [45]3 years ago

3 0

Answer: A 20kg Stone traveling an 10 m/s

Explanation:

The Formula for Kinetic Energy is KE = 0.5 x mv², using this equation you can then find the item with the most Kinetic Energy in Joules (J) 0.5 x 20 x 10 = 200 Joules.

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Which of the following has the smallest radius? <br> A. O^2- <br> B. F^- <br> C. Li^- <br> D. Be^2+

nordsb [41]

Answer : The correct option is, (D) $Be^{2+}$

Explanation :

Effective nuclear charge : It is defined as the attraction of the protons present in the nucleus of an atom to the outermost electrons.

For ions, the effective nuclear charge changes than the neutral atom.

There are two types of ions:

Cations: They are formed when an atom looses its valence electrons. They are positive ions.

Anions: They are formed when an atom gain electrons in its outermost shell. They are negative ions.

For positive ions, the removal of electron increases the nuclear charge for an outermost electron because the outermost electrons are more strongly attracted by the nucleus. Thus, the effective nuclear charge increases for cations.

From this we conclude that, the size of the cation is smaller than their neutral atom because it has less number of electrons while its nuclear charge remains the same. So, the nucleus attracts the electron more towards itself and leads to the decrease in size.

For negative ions, the addition of electron decreases the nuclear charge for an outermost electron because the outermost electrons are less strongly attracted by the nucleus. Thus, the effective nuclear charge decreases for anions.

From this we conclude that, the size of the anion is greater than their neutral atom because it has more number of electrons while its nuclear charge remains the same. So, the nucleus attracts the electron less towards itself and leads to the increase in size.

Thus, the increasing order of radius of ions will be:

$Be^{2+}$

Hence, the smallest radius of ion is, $Be^{2+}$

4 0

4 years ago

A 68-kg man whose average body temperature is 39°C drinks 1 L of cold water at 3°C in an effort to cool down. Taking the average

Dmitry [639]

Answer:

<h3>The man's average body temp. will fall by 0.6°C to 38.4°C</h3>

Explanation:

The enthalpy (heat content) of the water, using a datum of 0°C, is

Hw = Mw kg x Cp,w (specific heat capacity kJ/kg °C) x Tw °C

= 1 kg x 4.18 kJ/kg°C x 3°C = 12.5 kJ

Hman (pre drink) = 68 kg x 3.6 kJ/kg/°C x 39°C = 9547 kJ

So Hman (post drink) = H (pre drink) + Hw = 9547 + 12.5 = 9559.5 kJ because no heat is lost immediately.

But Hman (after drink) has mass 68 + 1 = 69 kg

Also his new Cp will be approx (3.6 x 68/69) + (4.18 x 1/69) = 3.608 kJ/kg°C

So Hman = 9559.5 kJ (from above) = 69 kg x 3.608 kJ/kg°C x Tnew

Therefore the man's new overall temp. = 38.4°C which is a drop of 0.6°C

8 0

3 years ago

What is the density of 10cm^3 volume of water that has a mass of 10g?

prisoha [69]

Answer:

The answer is

Explanation:

The density of a substance can be found by using the formula

$density = \frac{mass}{volume} \\$

From the question

mass = 10 g

volume = 10 cm³

It's density is

$density = \frac{10}{10} = 1 \\$

We have the final answer as

Hope this helps you

3 0

4 years ago

Read 2 more answers

Which of the following factors affect the vapor pressure of a liquid? Check all that apply. View Available Hint(s) Check all tha

trasher [3.6K]

Answer:

Vapour pressure of liquid is affected by its TEMPERATURE, TYPE OF LIQUID, ADDITION OF SOLUTES.

Explanation:

Vapor pressure is the pressure exerted by a vapor in equilibrium with its liquid. Mathematically, the vapor pressure of liquid is written as:

In (Pvap) = -ΔHvap / R * (1/T) + C

ΔHvap is the enthalpy of vaporization and it is constant for specific liquid, T is the temperature and C is a constant. Temperature therefore affect the vapor pressure of a liquid as increase in temperature can cause an increase in vapor pressure.

The type of liquid also affect the vapor pressure. If the molecules bind to each other strongly in the liquid, it increases vapor pressure to be exerted by the liquid but if the type of liquid is one with weak forces of attraction, the vapor pressure is reduced.

Addition of solute to the liquid increases the boiling temperature of liquids thereby reducing it's vapor pressure.

6 0

3 years ago

What is the theoretical yield of vanadium, in moles, that can be produced by the reaction of 1.0 mole of V2O5 with 4.0 mole of c

yuradex [85]

Answer:

Theoretical moles of V are 1.6 moles

Explanation:

The theoretical yield of a reaction is defined as the amount of product you would make if all of the limiting reactant was converted into product.

In the reaction:

V2O5(s) + 5Ca(i) → 2V(i) + 5CaO(s)

Based on the reaction, 1 mol of V2O5 needs 5 moles of Ca for a complete reaction. As there are just 4 moles, <em>limiting reactant is Ca.</em> As there are produced 2 moles of V per 5mol of Ca, Theoretical moles of V are:

4 moles of Ca × (2mol V / 5Ca) = <em>1.6 moles of V</em>

I hope it helps!

5 0

3 years ago