the first periodic table of elements mandeleev created contained only 45 elements. true or false

Answers

Answer 1
Fales its either 61 or 32
Answer 2

Answer:

false

Explanation:


Related Questions

Determine the electric potential energy for the array of three charges in the drawing, relative to its value when the charges are infinitely far away and infinitely far apart.

Answers

Although we do not have the diagram needed to answer this question, we can provide general information in that electrical potential energy is calculated based on the charges and the distance between them.

How do we calculate electric potential energy?

This energy can be calculated using the value of the charges along with the distance between them with the formula Energy = [tex]k\frac{q1q2}{r}[/tex] in which q represents the charges whilst r represents the distance of separation. As we can see these values are inversely proportional to one another.

Therefore, we can confirm that we can calculate electric potential energy using the charges and the distance between them, which will be inversely proportional to one another.

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Why does the moon turn red during a lunar eclipse?.

Answers

Answer:

The moon is turning red because being that the moon doesn't have any light of it's own, the Earth moves between the Sun and the moon, disrupting the light supply for the Moon.

During a new eclipse the moon turns red because the only sunlight reaches the moon and passes through earth atmosphere.the more dust or clouds in earth atmosphere during eclipse,the redder the moon gets

A lower ramp will be longer, allowing for less force to be used, but makes an object travel a greater distance.
True or false??

Answers

Answer: READ WHOLE THING ***

A ramp is an example of an inclined plane. Think back to the example of the ramp and the moving truck. The ramp reduced the amount of force needed to lift the box by moving it over a greater distance. The longer an inclined plane, the less force is required to move an object upward.

Hope this helps :)

True, a lower ramp will be longer, allowing for less force to be used, but makes an object travel a greater distance.

What is potential energy?The energy possessed by a body due to its position.The higher the object from earth's surface the higher potential energy it will have.Thus , if we want to throw any object in sky far away , we have to apply more force.Similarly , if the ramp will be longer , then it will consume less force to move an object over it so the object will travel a greater distance.

Therefore , a lower ramp will be longer, allowing for less force to be used, but makes an object travel a greater distance.

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When an object has a electrical charge, electrons are? _____ when it comes in contact with other objects

Answers

Electrons are exchanged

In a diving team, you are the team leader and you have three orientation in a trip 1-the red sea (low density) , 2-Dead sea (high density), 3-Deep lake (Pure water),which place is the best to dive in with your team.explain your opinion.

Answers

Answer:

I choose red sea, because while diving, it will be more easier if the upward force is less(upthrust). since the upthrust increase with increase with density, it will be much difficult to dive in Dead sea than red sea.

1. since red sea has less density, it would have the minimum upthrust, which results in less resistance while diving.

it is also because, the pressure inside the liquid at same depth will be less in red sea, due to its density.

PLEASE MARK BRAINLIEST.

Which is the correct scientific notation of the number 0.0006817

Answers

Answer:

6.817 x 10^-4

Explanation:

You first need to put the decimal between the ones and tenths (6.8), then you count back to the original decimal point. If you are counting to the left then its going to be a negative exponent but if you count towards the right, it'll be a positive exponent. So from 6.817 to 0.0006817, it is 4 places back. Thats how you get the answer. Hope this helps a bit

Answer:

6.817 x 10^-4

Explanation:

First move the decimal between the ones and tenths (6.8), then count back to the original decimal point if you are counting to the left then its going to be a negative exponent but if you count towards the right it'll be a positive exponent. From 6.817 to 0.0006817, it is 4 places back, nd this is how you get the answer.

If the sum of all the forces acting on a car is zero, then the speed of the car?

Answers

Answer: If all forces acting on a car are zero, than the cars speed is zero since there are no forces to push or pull the car :)

Explanation:

The mass of a large car is 1000 kg. How much force would be required to accelerate the car at a rate of 3msec2

Answers

Answer:

3000 N

Explanation:

We have,

• Mass, m = 1000 kg

• Acceleration, a = 3 m/s²

We have to find force required, F.

[tex]\longrightarrow[/tex] F = ma

[tex]\longrightarrow[/tex] F = 1000 × 3 N

[tex]\longrightarrow[/tex] F = 3000 N (Answer)

Think of an example from real life that can be explained with Newton's Third Law.

Answers

Answer:

when you jump, your legs apply force on the ground that applies an equal and opposite reaction that make you jump

•If the car and truck collided, which
direction would the two cars move. Be
sure to explain your answer in terms of
momentum.

Answers

Answer:

The cars would both move in the direction with the greatest momentum.  We know the truck would have the greatest momentum due to having the greatest mass. Plus, factors which affects momentum are mass and velocity.    

Thus, the car would move forward towards the direction of momentum of the truck. Both will continue to move at the same velocity.

E.g. truck hits the back of a stationary car, both will move forward, to the right & travelling at the same speed, but lower than the initial velocity of the truck. Now the total the total momentum before the collision is the same as the total momentum after the collision; as a result, momentum has been conserved.

Hope this helps!

One piece of evidence that can help astronomers sort out how the planets in our solar system formed is

Answers

Answer:

[tex]\huge\boxed{\sf Circumstellar\ discs }[/tex]

Explanation:

Astronomers discovered matter made up of gas, dust or asteroids etc. around nearby stars. This matter is called circumstellar disc (due to it being ring-shaped). These circumstellar discs are materials out of which planets form.

Circumstellar discs are one piece of evidence that can help astronomers sort out how the planets in our solar system were formed.

[tex]\rule[225]{225}{2}[/tex]

Hope this helped!

~AH1807

what would happen to the temperature on mercury during the day if a sunspot was directly in line with it's surface?

Answers

Answer:

mind-bogglingly hot

Explanation:

If a sunspot were pointed right at Mercury in this way, the planet would become even more mind-bogglingly hot. Sunspots look dark in our visual spectrum, so we might suspect that they are colder (or at least less hot) than the rest of the Sun; but in fact, they are hotter.

Globally, the winter of 2014–15 was the warmest winter on record at that time, but it sure didn’t seem that way for most of the eastern United States. This region experienced record-low temperatures and extreme snowfall, especially in the northern and coastal areas. During this period of extreme cold and snow, it was not uncommon to see comments on social media disputing climate change. For example, some commenters took pictures of huge piles of snow and added comments such as, "This doesn’t look like global warming."


Do these commenters have a point? Should extreme snowfall over the course of a season cast doubt on the theory of global climate change? Make a scientific argument explaining why you agree or disagree with these commenters.

Answers

Answer:

I need help on this to omg

Explanation:

A periodic wave has a wavelength of 2m and has a speed of 45 m/s what is the frequency

Answers

Answer:

f = 22.5 Hz

Explanation:

speed of wave = v

frequency = f

wave length = l

v = lf → f = v/l → f = 45/2 → f = 22.5 Hz

In practice, it will take longer than a electric kettle to boil the water in a normal kettle. Explain why.

Please answer correctly..
Please help !!
Will give the brainliest !!!​

Answers

Explanation:

electric kettle works so quickly is by using a relatively large electric current.

The amount of heat produced is proportional to the current squared,

so bigger currents produce much more

heat—and heat things much more

quickly—than smaller ones.

Water in an electric kettle boils much faster when compared to normal kettle mainly because of two reasons :-

(•) In normal kettle, heat is supplied directly onto the kettle's base. As it is cold in nature, it takes time for the kettle base to be heated and then only the heat passes through water.

On the other hand, in electric kettle, the electric current wave passes directly through the water, hence it takes less time to heat the water.

(•) Water is a good absorber of electric current, but is a poor absorber of heat. Consider if it takes 2 minutes for electric to pass through water, then it will take 9 minutes for the heat to pass through water.

It is due to these major reasons to why water boils faster in electric kettle than in normal kettle.

-----------------------------------

If you have any doubts regarding the answer, feel free to ask it in comments !

Hope this answer's your query ...

Object A mass a mass of 5 kg. Object B has a mass of 8 kg. If a force of 100 N is applied to each object, identify which object will accelerate the most and which will accelerate the least.

Answers

Object A will accelerate the most as there’s less inertia to overcome.

True or false. A separation technique that can be used for this investigation is centrifugation.

Answers

The answer is true because I just did this

Select the correct answer. Which term describes the ability to repay debt? A. capacity B. creditworthiness C. capability

Answers

Answer:

the answer is capacity

Explanation:

The conductor is initially electrically neutral, and then a charge +q is placed at the center of the hollow space. Suppose the conductor initially has a net charge of +9q instead of being neutral. What is the total charge on the interior and on the exterior surface when the +q charge is placed at the center? Please explain the answer as well..

Answers

Hi there!

If a +q charge is placed in the center of a hollow conductor, a charge of -q will be induced in the interior of the shell.

Thus, with the conservation of charge:


[tex]q_{outer} + q_{inner} = q_{total}\\\\q_{outer} - q = 9q[/tex]

Solve for the outer charge:

[tex]q_{outer} = q + 9q = 10q[/tex]

Therefore, the INTERIOR has charge -q and EXTERIOR has charge 10q.

if velocity is in m/s and time is in sec, what is the unit of acceleration?​

Answers

The unit of acceleration would be m/s² :)

Introduction for Home economics project​

Answers

Answer:

study of everything that helps to improve the home and the family

Explanation:

Answer:

Home economics, or family and consumer sciences, is a subject concerning human development, personal and family finance, housing and interior design, food science and preparation, nutrition and wellness, textiles and apparel, and consumer issues.

Explanation:

I hope it will help you....

#carryonleraning

the 20 kg at angle of 53⁰ in an inclined plane is realsed from rest the coefficient of friction bn the block and the inclined plane are ųs=0.3 and ųk=0.2
A) would the block move
B) if it moves what is its speed after it has descended a distance of 5m down the plane​

Answers

Given :-

A 20kg block at an angle 53⁰ in an inclined plane is released from rest .[tex]\mu_s = 0.3 \ \& \ \mu_k = 0.2[/tex]

To Find :-

Would the block move ?If it moves what is its speed after it has descended a distance of 5m down the plane .

Solution :-

For figure refer to attachment .

So the block will move if the angle of the inclined plane is greater than the angle of repose . We can find it as ,

[tex]\longrightarrow \theta_{repose}= tan^{-1}(\mu_s)[/tex]

Substitute ,

[tex] \longrightarrow \theta_{repose}= tan^{-1}( 0.2)[/tex]

Solve ,

[tex]\longrightarrow\underline{\underline{\theta_{repose}= 16.6^o }}[/tex]

Hence ,

[tex]\longrightarrow\theta_{plane}>\theta_{repose}[/tex]

Hence the block will slide down .

Now assuming that block is released from the reset , it's initial velocity will be 0m/s .

And the net force will be ,

[tex]\longrightarrow F_n = mgsin53^o - \mu_k N [/tex]

Substitute, N = mgcos53⁰ ( see attachment)

[tex] \longrightarrow ma_n = mgsin53^o - \mu_k mgcos53^o [/tex]

Take m as common,

[tex] \longrightarrow\cancel{m }(a_n) = \cancel{m}( gsin53^o - \mu gcos53^o)[/tex]

Simplify ,

[tex] \longrightarrow a_n = gsin53^o - \mu_k g cos53^o[/tex]

Substitute the values of sin , cos and g ,

[tex] \longrightarrow a_n = 10( 0.79 - 0.2 (0.6)) [/tex]

Simplify ,

[tex] \longrightarrow a_n = 10 ( 0.79 - 0.12 ) \\\\ \longrightarrow a_n = 10 (0.67)\\\\ \longrightarrow \underline{\underline{a_n = 6.7 m/s^2}}[/tex]

Now using the Third equation of motion namely,

[tex] \longrightarrow2as = v^2-u^2[/tex]

Substituting the respective values,

[tex] \longrightarrow2(6.7)(5) = v^2-(0)^2 [/tex]

Simplify and solve for v ,

[tex] \longrightarrow v^2 = 67 m/s\\\\\longrightarrow v =\sqrt{67} m/s \\\\\longrightarrow\underline{\underline{ v = 8.18 m/s }} [/tex]

Hence the velocity after covering 5m is 8.18 m/s .

Davina accelerates a box across a smooth frictionless horizontal surface over a displacement of 18. 0 m with a constant 25. 0 n force angled at 23. 0° below the horizontal. How much work does she do on the box?.

Answers

work and force

w = f cos 23 . d

w = 25 cos 23° . 18

w = 414.23 J

An object experiences a certain net force that causes a certain acceleration. If the net force on the object is
tripled, what happens to the acceleration of the object?

Answers

Answer:

it increases

Explanation:

equal to opposite force so it would return the amount applied on it

If an object experiences a certain net force that causes a certain acceleration. If the net force on the object is tripled , then the acceleration of the object would become tripled as well assuming the mass of the object is constant.

What is Newton's second law ?

Newton's Second Law states that The resultant force acting on an object is proportional to the rate of change of momentum.

As given in the problem if an object experiences a certain net force that causes a certain acceleration. If the net force on the object is

tripled,

If a specific net force acting on an item results in a specific acceleration. Assuming the mass of the item remains constant if the net force acting on it is tripled, the acceleration of the object would also be tripled.

Thus, the acceleration of the object would get tripled.

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What is the relationship between the shock wave of an explosion and sound?

Answers

In particular, shock waves travel faster than sound, and their speed increases as the amplitude is raised; but the intensity of a shock wave also decreases faster than does that of a sound wave, because some of the energy of the shock wave is expended to heat the medium in which it travels.

What is the working principle of thermometer?​

Answers

it tells the temperature of something or someone

A learner has a mixture of sand and water. The best method to separate this solution would be ?

Answers

Answer:

An filtration is the answer.

Aluminum can be made into foil because aluminum has high?

Answers

Answer:

Aluminum can be made into foil because aluminum has high ductile.

Explanation:

Answer:

Because it is highly ductile

A certain lever has a mechanical advantage of 5.5 how heavy of a load could the lever lift with an input force of 20.0 N

Answers

Answer:110N

Explanation:

ma=f in/ f out (formula)

Input: 20.0N

Ma:5.5

Output:?

^ given information

Plug the numbers into the equation ~
5.5= 20N/?
5.5x20=110N

If a certain lever has a mechanical advantage of 5.5, then the leaver would be able to lift a load of 110 Newtons  with an input force of 20.0 N

What is the mechanical advantage?

Mechanical advantage is defined as a measure of the ratio of output force to input force in a system, It is used to analyze the forces in simple machines like levers and pulleys.

Mechanical advantage = output force(load) /input force (effort)

As given in the problem a certain lever has a mechanical advantage of 5.5, then we have to find out how heavy of a load could the lever lift with an input force of 20.0 N,

Mechanical advantage = output force(load) /input force (effort)

5.5 = load / 20.0 Newtons

load = 5.5 × 20

       = 110 Newtons

Thus, the leaver would be able to lift a load of 110 Newtons  with an input force of 20.0 N

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Salem walked 60 m in 5 seconds, his average speed is.

Answers

Answer:

12m/s

Explanation:

60/5=12

Answer:

Explanation:

Solution,

Distance(d)=60m

Time(t)=5sec

Now,

A.speed=d/t

A.speed=60/5=12m/s

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