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2 years ago

Anthracite is so hard and pure it is also referred to as a _____.

1 answer:

6 0

Anthracite is also referred to as hard coal because it is so hard and pure. It is very hard and highly compacted with variety of coal that has submetallic luster. It has highest carbon content, the lowest impurities, and highest density of energy of all the coal deposits.

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Fatima is designing an advanced graphics card for a next-generation video game system. She needs to be able to precisely control

Salsk061 [2.6K]

Answer:svbehsbss c

Explanation:

D xxxx

8 0

1 year ago

NEED HELP ASAP ITS DUE TODAY THESE QUESTIONS

beks73 [17]

Density can be defined as the mass of the substance in unit volume.

Density = mass / volume

Hence, g/mL and kg/L can be used as the units of density.

Those units are interchangeable because when converting one unit into other one nothing will happen to the value.

That is because when converting the g into kg, you have to multiply the value by 1 x 10⁻³. When converting mL into L, you should again multiply the volume by 1 x 10⁻³. Then those 1 x 10⁻³ will cancel off and the original value will remain as same.

Answer is 2.70 g/mL.

Explanation;

Mass of the block = 146 g

Volume of the block = length x width x height

= 6.0 cm x 3.0 cm x 3.0 cm

= 54 cm³ = 54 mL

Density = mass / volume

= 146 g / 54 mL

= 2.70 g/mL

Answer is 3.39 g/mL.

Explanation;

When immersing an object in a solution, the increased volume indicates the volume of that object.

Hence,

Volume of the object = increased volume of water level

= final volume - initial volume

= 27.8 mL - 21.2 mL

= 6.6 mL

Mass of the object = 22.4 g

Density = Mass / Volume

= 22.4 g / 6.6 mL

= 3.39 g/mL

Accepted value is the value that scientists and community accept as true. This is a theoretical value.

But the measured value is the value that you obtain from doing experiments. This is the actual value.

If your measured value is more close to the accepted value, then your measured value is more precise. But, if your measured value is far away from accepted value means that your value is not precise and there may have some errors.

Answers : Percent error is 9.11 %

The element which has 7.13 g/cm³ as density is Zinc (Zn).

Explanation;

Percent error can be calculated by using following formula.

% error = ( (measured value - accepted value) / accepted value ) x 100%

= ( (7.78 g/cm³ - 7.13 g/cm³) / 7.13 g/cm³ ) x 100%

= 9.11 %

6 0

2 years ago

Which two notations represent isotopes of the same element

Mumz [18]

The two notations that represent isotopes of the same element is the one that represented in option 1
The lower number is the number of protons while the upper number is the atomic weight

hope this helps

6 0

2 years ago

Read 2 more answers

Which element is reduced in this reaction? 2kmno4 3na2so3 h2o→2mno2 3na2so4 2koh

erik [133]

In a redox chemical reaction, one species gets reduced and another gets oxidized. Manganese element is reduced in this reaction.

<h3>What is oxidized and reduced?</h3>

In a redox reaction, the increase or decrease in the oxidation number and electrons results in the reduction and oxidation of the chemical species. The oxidation and reduction occur simultaneously in a reaction.

The oxidation number of Mn in permanganate ion was +8 on the left side and decreased to +4 on the right side of the equation. Potassium permanganate is an oxidizing agent that has reduced the manganese ion of the permanganate ion.

Therefore, manganese is reduced.

Learn more about reduction and oxidation here:

brainly.com/question/2427143

#SPJ4

3 0

1 year ago

What volumes of 0.200 M HCOOH and 2.00 M NaOH would make 500. mL of a buffer with the same pH as one made from 475 mL of 0.200 M

Fed [463]

36 ml of NaOh and 464 ml of HCOOH would be enough to form 500 ml of a buffer with the same pH as the buffer made with benzoic acid and NaOH.

What is benzoic acid found in?

Some natural sources of benzoic acid include: Fruits: Apricots, prunes, berries, cranberries, peaches, kiwi, bananas, watermelon, pineapple, oranges.
Spices: Cinnamon, cloves, allspice, cayenne pepper, mustard seeds, thyme, turmeric, coriander.

Calculate the amount of moles in NaOH and benzoic acid. This calculation is done by multiplying molarity by volume.

Amount of moles of NaOH -2 × 0.025 = 0.05 mol

Amount of moles of benzoic acid 2 × 0.475 = 0.095 mol

In this case, we can calculate the pH produced by the buffer of these two reagents, as follows

$pH = pKa + log\frac{base}{acid}$