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3 years ago

How is friction a good thing and a bad thing?

1 answer:

6 0

1. It stops objects from sliding endlessly.
2. It's the reason why we're able to walk

Bad:
1. Decreases efficiency since some energy is wasted and turns to heat
2. Damages equipment/objects like when you slide it on the floor

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Based on your answer in part B, arrange the five elements in order of their reactivity. Drag the most reactive element to the to

amm1812

Answer: Order of the elements from most reactive to least reactive is:

Mg > Zn > Fe > H > Cu

Explanation: Reactivity of the elements is the tendency of the elements to loose or gain electrons with ease.

As, all the given elements are metals, so the metals which will loose electrons easily will be more reactive. To study the reactivity of metals, we use reactivity series.

The metals which are more reactive are placed on the top of the reactivity series and which are less reactive are placed at the bottom.

Hence, the order of the elements from most reactive to least reactive is:

Mg > Zn > Fe > H > Cu

Reactivity series is attached below.

6 0

3 years ago

Polar molecules have _____.

Ksju [112]

Answer:

B. Charges ( a slight positive charge on one end, and a slight negative charge on the other).

4 0

2 years ago

Read 2 more answers

Balance the equation below for the reaction between hydrogen and chlorine, using the smallest whole-number

Elanso [62]

H2(g) + Cl2(g) = 2 HCl(aq) (balanced equation)
1, 1, 2 (coefficients)

3 0

3 years ago

Consider the following system at equilibrium:A(aq)+B(aq) <---> 2C(aq)Classify each of the following actions by whether it

velikii [3]

Explanation:

Any change in the equilibrium is studied on the basis of Le-Chatelier's principle.

This principle states that if there is any change in the variables of the reaction, the equilibrium will shift in the direction to minimize the effect.

On addition of reactant at equilibrium shifts the equilibrium in forward direction.
On addition of product at equilibrium shifts the equilibrium in backward direction.
On removal of reactant at equilibrium shifts the equilibrium in backward direction.
On removal of product at equilibrium shifts the equilibrium in forward direction.

$A(aq)+B(aq)\rightleftharpoons 2C(aq)$

Reactants = A , B

Product = C

1. Increase A

On increasing the amount of A at equilibrium will shift the equilibrium in forward or rightward direction.

2. Increase B

On increasing the amount of B at equilibrium will shift the equilibrium in forward or rightward direction.

3. Increase C

On increasing the amount of C at equilibrium will shift the equilibrium in backward or leftward direction.

4. Decease A

On decreasing the amount of A at equilibrium will shift the equilibrium in backward or leftward direction.

5. Decease B

On decreasing the amount of B at equilibrium will shift the equilibrium in backward or leftward direction.

6. Decease C

On decreasing the amount of C at equilibrium will shift the equilibrium in forward or rightward direction.

7. Double A and Halve B

Equilibrium constant of the reaction = K

$K=\frac{[C]^2}{[A][B]}$

On doubling A and halving B, equilibrium constant of the reaction = K'

$K'=\frac{[C]^2}{[2A][\frac{B}{2}]}=\frac{[C]^2}{[A][B]}$

The value of equilibrium constant K' is equal to K, which means that equilibrium will not shift in any direction.

8. Double both B and C

Equilibrium constant of the reaction = K

$K=\frac{[C]^2}{[A][B]}$

On doubling B and C, equilibrium constant of the reaction = K'

$K'=\frac{[2C]^2}{[A][2B]}=\frac{4[C]^2}{[A][2B]}=\frac{2[C]^2}{[A][B]}$

K' = 2 K

The value of equilibrium constant K' is double the K, which means that product is increasing which means that equilibrium will shift in backward or leftward direction.

5 0

3 years ago

By what quantity must the heat capacity be divided to obtain the specific heat of that material

masha68 [24]

<span>Heat capacity of an object, is the amount of heat energy or thermal energy (unit: Joule) needed to raise the temperature of the object by 1 degree celsius. Unit of heat capacity is J/°C

Larger object will surely need larger amount of thermal energy to raise its temperature. If you compare 1 litre of water with 0.5 litre of water, the 1L water will have two times the heat capacity.

It will be more useful to compare specific heat capacity, because then it is the amount of heat energy or thermal energy (unit: Joule) needed to raise the temperature of 1 unit mass of the object by 1 degree celsius. You can then compare between 1 unit mass of water and 1 unit mass of iron.
Water has higher specific heat capacity than iron, meaning that you need more energy to heat up 1kg of water, then to heat up 1kg of iron.

The unit will then be J/(kg °C) or J/(g °C).
</span>

6 0

3 years ago