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3 years ago

why is cobalt placed before nickel on the periodic table of elements even though it has a higher average atomic mass than nickel

2 answers:

8 0

Just because it has a smaller atomic number. Elements are not lined up according to the higher average atomic mass, but rather according to the higher atomic number.

Rus_ich [418]3 years ago

7 0

Because it has a smaller atomic number. Elements are not lined up according to the higher average atomic mass, but rather according to the higher atomic number.

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Please Help Why is laboratory safety important? Describe a scenario illustrating your reason(s).

Virty [35]

So that you can learn while being safe. Wearing goggles, for eye protection when dealing with chemicals

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3 years ago

A patient taking _______ would have a history of mental depression.

ohaa [14]

The answer is Prozac

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3 years ago

Does it take more, less, or the same amount of heat to melt 1.0 kg of ice at 0°C, or to bring 1.0 kg of liquid water at 0°C to t

Murljashka [212]

Answer : It takes less amount of heat to metal 1.0 Kg of ice.

Solution :

The process involved in this problem are :

$(1):H_2O(s)(0^oC)\rightarrow H_2O(l)(0^oC)\\\\(2):H_2O(l)(0^oC)\rightarrow H_2O(l)(100^oC)$

Now we have to calculate the amount of heat released or absorbed in both processes.

For process 1 :

$Q_1=m\times \Delta H_{fusion}$

where,

$Q_1$ = amount of heat absorbed = ?

m = mass of water or ice = 1.0 Kg

$\Delta H_{fusion}$ = enthalpy change for fusion = $3.35\times 10^5J/Kg$

Now put all the given values in $Q_1$ , we get:

$Q_1=1.0Kg\times 3.35\times 10^5J/Kg=3.35\times 10^5J$

For process 2 :

$Q_2=m\times c_{p,l}\times (T_{final}-T_{initial})$

where,

$Q_2$ = amount of heat absorbed = ?

m = mass of water = 1.0 Kg

$c_{p,l}$ = specific heat of liquid water = $4186J/Kg^oC$

$T_1$ = initial temperature = $0^oC$

$T_2$ = final temperature = $100^oC$

Now put all the given values in $Q_2$ , we get:

$Q_2=1.0Kg\times 4186J/Kg^oC\times (100-0)^oC$

$Q_2=4.186\times 10^5J$

From this we conclude that, $Q_1$ that means it takes less amount of heat to metal 1.0 Kg of ice.

Hence, the it takes less amount of heat to metal 1.0 Kg of ice.

5 0

3 years ago

A 253 g block of wood has the following dimensions: Length 15.24 cm Width 6.64 cm Height 3.56 cm What is the density of the wood

yanalaym [24]

Answer:

0.7 g/cm³

Explanation:

hey there,

< The formula for density is $p = \frac{m}{v}$ where m = mass, v = volume, and p = density. An easy way to remember the formula is density equals love. I found this easy to remember because p = ♡ and when you think about it, if you split the heart in half through the middle like a fraction, it will make $\frac{m}{v}$ (if you don't understand what I'm saying, try writing it out and you will be able to see what I'm talking about!)

We already know that the block is 253 g so the mass is 253 g.

To find the volume, always multiply the 3 values width, length, and height whenever you are trying to find the volume of a block.

15.24 cm x 6.64 cm x 3.56 cm = 360.25 cm³

Now plug it into the formula. $p = \frac{m}{v}=\frac{253}{360.25} = 0.7 g/cm$ ³ >

Hope this helped! Feel free to ask anything else.

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3 years ago

How could you use a model to show the cause-and-effect relationship between Earth's rotation and the apparent motion of the star

Masteriza [31]

Question:

How could you use a model to show the cause-and-effect relationship between Earth's rotation and the apparent motion of the stars across the night sky?

Answer:

Gravity? or density because of the pull from the sun.

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3 years ago

Read 2 more answers