gold has a density of 19.3 g/ml. if you have 4.0 grams of gold, what is the volume of the sample

Answer:

homogeneous solution

Explanation:

Hoped that helped :)

Answer:

A mixture

Explanation:

When salt dissolves in water mixture is formed.

It can be separated by evaporating then condensing the water.

Both substances retain their old property.

Hope this helps

Answer:

the volume of water with egg was 200 and when we removed the egg become 125

Explanation:

200ml - 125ml = 75ml

so 1 millimeter = 1 centimeter cubic

so

75ml = 75 cm3

the answer is 75cm3

Answer: 308.649 K

Explanation:

Temperature in Celsius would be converted to Kelvin (K), which is the widely accepted S.I units for measuring Temperature in Chemistry.

Kelvin (K) = 273 + Celcius

               =  273 + 35.649 C

               =  308.649 K

Answer:

There is only 1 sig figures in 6

Explanation:

There is no 0 after it so it is considered as only 1 significant figure

Answer:

protons and neutrons located within the nucleus, with electrons in orbitals surrounding the nucleus.

Answer:it B,

Explanation: you make two liquids react together. Energy is being given off because light is emitted. The electrons of the liquids must be losing energy in order to produce light.

Answer:

D) lithium

Sodium Chloride is salt which is oviously present.

Oxygen is also present because fish use their gills to get oxygen from water.

Plants are present under ocean which release Carbon dioxide.

(1) Islands are always surrounded by bodies of water, in this case oceans. These islands tend to have more 'stable climates' and 'smaller temperature fluctuations' due to the specific heat of water, which is quite high, 4180 J/kg C. The higher the specific heat, the more the energy needed to raise the temperature of the substance. Land requires less energy to raise it's temperature than water due to it's lower specific heat. Thus, islands tend to have more stable temperatures than regions surrounded by land.

(2) Based on the conditions provided, the thermochemical equation for the reaction should be:  

2NaHCO₃ (s) ---> Na₂CO₃ (s) + H₂O (g) + O₂ (g)

This is a decomposition reaction, as it explains that the baking soda breaks down into the products. All we had left to do is balance the equation, adding 2 as the coefficient of the reactant.

(3) Let's rewrite the given equations:

First chemical reaction: H₂(g) + F₂(g)  ---> 2HF(g), ΔH₁ = –537 kJ.

Second chemical reaction: C(s) + 2F₂(g) ---> CF₄(g), ΔH₂ = –680 kJ

Third chemical reaction: 2C(s) + 2H₂(g) ---> C₂H₄(g), ΔH₃ = +52.3 kJ.

Fourth chemical reaction: C₂H₄(g) + 6F₂(g) ---> 2CF₄(g) + 4HF(g), ΔH₄ = ?

Now the 'fourth chemical reaction' is the one in which we need to determine the enthalpy:

ΔH₄ = 2(ΔH₁) + 2(ΔH₂) - ΔH₃,

ΔH₄ = 2(–537) + 2(–680) - 52.3 = -2486.3 kJ

Answer:

The answer to this is simple.  

There is a school of thought that believes that natural fires are necessary.

Explanation

They are required to reduce the density of the forests that are so thick that when they eventually burn, the effects are usually catastrophic. According to one source, some of these forests are over a hundred years old. When eventually these kinds of forests catch fire, they become very hard to manage and the destruction the leave are usually worse off than if they had not been allowed to so heavy and impenetrable.  

Another reason put forward by this school of thought is that the countries who own these forests have politicised wildfires using them as an excuse to attract international funding/assistance because the fires are depleting the worlds protective greenery/earth biggest natural oxygen factory.

Cheers!

Answer:

The volume of mercury is 0.368mL .

Explanation:

You have to apply Density formula, D = mass/volume. Then, substitute the following values into the formula :

[tex]density = \frac{mass}{volume} [/tex]

[tex]let \: density = 13.6 , mass = 5[/tex]

[tex]13.6 = \frac{5}{vol} [/tex]

[tex]13.6 \times vol = 5[/tex]

[tex]vol = 5 \div 13.6[/tex]

[tex]vol = 0.368ml \: (3sf)[/tex]

Volume of mercury metal of mass 5.00 g and density 13.6 g/ml will be

68 ml.

Density of metal can be calculated by mass per unit volume. Density of a substance is directly proportional to mass and inversely proportional with volume.

Density= mass/ volume.

Volume= density * Mass

           = 13.6g/ml * 5 g

          = 68 ml.

Density of substance is directly proportional with mass and and inversely proportional with volume. If mass of the substance increases density increases, if volume of the substance decreases then  density increase.

Therefore, Volume of mercury metal of mass 5.00 g and density 13.6 g/ml will be 68 ml.

To learn more about volume, refer to the link:

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Answer:

c

Explanation:

Answer:

c

Explanation:

Answer:

0.090 J/(mmol·°C) × (1000 mmol/mole × 1 kJ/(1000 J)) = 0.090 kJ/mole

Explanation:

The unit of conversion from kilo-Joules to Joules is given as follows;

1000 Joules = 1 kilo-Joule

The unit of conversion from milimoles to moles is given as follows;

1000 milimoles = 1 Mole

Therefore, we have

The value of the given expression is 0.090 J/(mmol·°C) × 1000 mmol/mole × 1 kJ/(1000 J) = 0.090 kJ/mole

0.090 J/milimole = 0.09 kJ/mole.

Answer:

A. Carbon

B. I, III

Explanation:

Carbon has four valence eletrons meaning that it is more stable than the other choices. A proton has mass and has a positive charge.

Answer:

When  wood is burnt , it turns into ashes which is a new substance and process is irreversible one,( chemical change)

When wood is cut into smaller pieces (firewood) this is a physical change

Explanation:

Answer:

can we see the type that is shown?

Answer:

True

Explanation:

Three families are found in the center portion of the periodic table are of iron, cobalt and nickel atoms.

Groups are the vertical columns of elements present in the periodic table in which elements of same valency and valence configuration is present.

In the periodic table total 18 groups are present starting from left side to right side. In the middle of the periodic table three families or groups of iron, cobalt and nickel atoms are present which are known by the name of group 8th, 9th and 10th of the periodic table.

So, three families are of iron, cobalt and nickel atoms.

To know more about groups, visit the below link:
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Answer:

Explanation:

Density of a substance can be found by using the formula

[tex]Density(\rho) = \frac{mass}{volume} [/tex]

From the question

Density = 2.5 g/mL

volume = 20 mL

To find the mass substitute the values into the above formula and solve for the mass

That's

Making mass the subject we have

mass = Density × volume

mass = 2.5 × 20

We have the final answer as

Hope this helps you

Answer:

mass=?,volume=20,density=2.5.

density=mass/volume.

which will be 2.5=mass/20

which is mass=2.5×20=50kg

Answer:

Refraction of waves involves a change in the direction of waves as they pass from one medium to another,so as water waves are transmitted from deep water into shallow water,the speed decreases,the wavelength decreases and the direction changes

Answer: 9000 - 1 significant figure

Explanation: Since you are multiplying, the number with the least amount of significant figures determines the number of significant figures in the answer. The number 9 has 1 significant figure and 1025 and has 4 significant figures so 9 has the fewest significant figures,  meaning your answer will be 1 significant figure.

Answer:

5 Significant Figures

Explanation:

Answer:

1. active site

2. substrate.

3. activity

4. cofactor

5. complex

6. coenzyme.

Explanation:

1. A substrate binds to an enzyme at the active site where the reaction occurs.

2. In a catalyzed reaction, a reactant is often called a  substrate.

3  activity is a measure of how fast an enzyme can convert the reagent to the  product.

4. An inorganic substance necessary for the function of some enzymes is called a cofactor.

5. When properly aligned, the enzyme and substrate form an enzyme-substrate (ES) complex.

6. A small organic molecule necessary for the function of some enzymes is  called a  coenzyme.

Answer:

[tex]\frac{6}{3} Li^{-}[/tex]

Explanation:

The number of protons and neutrons together create total atomic mass.

The number of protons determine what element it is on the Periodic Table.

The number of electrons v protons determine the charge of the atom.

Protons are positive, electrons are negative, neutrons have no charge.

Since there is 1 more electron than protons, the overall charge is going to be -1.

We are given that there are 3 protons, so that gives us the Lithium element with a -1 charge.

Add up the 3 protons with the 3 neutrons and we get 6 as the total atomic mass in this atom.

Gases, bc its expand the most upon heating because the intermolecular space is more than in solids or liquids.

intermolecular space = the space between each particles

Gases

the intermolecular space between gases is more than in solids and liquid

Answer:

skin

Explanation:

I think its skin because there is a protein that mostly makes up our skin, called keratin.

Answer:

(a) (i) 44

(ii) 88 and 36

(iii) 2.2

(b)H₂–C=C–H₂

Answer:  x=13/3

Explanation:

step 1: multiply both sides by 10: 36x=6x+130

step 2: subtract 6x from both sides 30x=130

step 3: divide both sides by 30: x=13/3

Answer:

Center for Disease Control (CDC)

Explanation:

All of the other answers can be changed and may not be backed with actual scientific evidence.

Answer:

CDC

Explanation: