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3 years ago

Elemental mercury was first discovered when a mercury oxide

1 answer:

3 0

Elemental mercury was first discovered when a mercury oxide was decomposed with heat. formingmercury metal and oxygen gas. is your anwser

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What is the specific heat of a substance if 690 J of heat are required to raise the temperature of a 100 g

tangare [24]

Answer:

Explanation:

8 0

3 years ago

Imagine that Ana has a block made of pure gold. If she cuts this block into two equal pieces, pick the statement that best descr

dimaraw [331]

Answer : The correct statement is:

The density of each piece is the same as that of the original block.

Explanation :

Intensive property : It is defined as a property of substance which does not change as the amount of substance changes.

Examples: Temperature, refractive index, density, hardness, etc.

According to question, if Ana has a block made of pure gold and she cuts this block into two equal pieces then the density of each piece is the same as that of the original block because density is an intensive property that does not changes until and unless material is changed.

That means density remains same as that of the original piece.

Hence, the correct statement is the density of each piece is the same as that of the original block.

6 0

3 years ago

Elements occur in a number of isotopic forms. In this problem, you will learn about the notation used to distinguish different i

alina1380 [7]

Answer:

Number of protons, Z = 14
Number of neutrons, N = 14

Explanation:

1) About isotopes:

Isotopes are different kind of atoms of the same element. Hence, they have the atomic number (Z), which is the number of protons, the same number of electrons (talking about to neutral atoms, not ions), and different number of neutrons N).

This is, it is the number of neutrons what distinguish different isotopes of an element.

2) About the notation used to distinguish different isotopes:

A superscript and a subscript, both to the left of the chemical symbol of the element, are used to distinguish different isotopes:

A ←------------- This superscript tells the mass number of the isotope

X ←--------- This is the chemical symbol of the element

Z ←-------------- This subscript is the atomic number of isotope

In our case, the notiation for the isotope of silicon is: ²⁸₁₄ Si

So, we have:

28 is the mass number (A)
14 is the atomic number (Z)
Si is the chemical symbol.

Now, you can answer the questions of the part A:

Number of protons: Z = 14

Number of neutrons N:

mass number = number of protons + number of neutrons

A = Z + N

⇒ N = A - Z = 28 - 14 = 14

In conclusion:

Number of protons, Z = 14
Number of neutrons, N = 14

5 0

3 years ago

When the coffee is brewed according to directions, a pound of coffee beans yields 50 cups of coffee (4 cups = 1 qt). How many kg

Xelga [282]

1 pound of coffee is said to yield 50 cups of coffee

So we need to find the pounds of coffee beans required to produce 250 cups

so if 50 cups need 1 pound of coffee beans

therefore 250 cups need - 1/50 x 250 = 5 pounds of coffee beans

since we have to find the amount of coffee beans needed in kg, we have to convert pounds to kg

1 pound = 0.45 kg

So if 1 pound is equivalent to 0.45 kg

then 5 pounds are equivalent to - 0.45 kg/pound x 5 pounds = 2.25 kg

therefore 2.25 kg of coffee beans are required

4 0

3 years ago

Read 2 more answers

Why do different elements make different color flames when you burn them?

Dovator [93]

When you heat an atom, some of its electrons are "excited* to higher energy levels. When an electron drops from one level to a lower energy level, it emits a quantum of energy. ... The different mix of energy differences for each atom produces different colours. Each metal gives a characteristic flame emission spectrum.

7 0

3 years ago