Coal contains carbon and other elements. Carbon dioxide forms when coal burns in the presence of oxygen. Which of these is the best evidence that a chemical reaction occurs when coal burns? Select one: A new substance is produced. Coal is made up of more than one element The shape of the coal changes. Oxygen is present.

Answer:

The answer is B

Explanation:

Answer:

Which answer gives both a positive impact and a negative impact associated with the effects of nitrogen- and phosphorus-enhanced fertilizers?

1. increased algal blooms and damage to drinking water

Right Answer 2. increased plant growth and damage to drinking water

3. increase in denitrifying bacteria and increase in plant growth

4. increase in a limiting resource and increase in denitrifying bacteria

Explanation:

Answer:

Isotopes are forms of a chemical element that have the same atomic number but differ in mass. 16O → 8 protons + 8 neutrons; a “light” oxygen); The relative amounts are expressed as either 18O/16O or δ 18O Oxygen - 18 (aka 18O → 8 protons + 10 neutrons; a “heavy” oxygen).

Answer:

P represents the atmosphere and Q represents the ocean.

Explanation:

Answer:

B

Explanation:

sight, hearing, smell, taste and touch

Answer:

Most easiest answer..

There are 5 senses in human body.☺️

Answer:

7

Explanation:

In the experiment to measure the heat absorbed by a material placed in

the Sun, we have;

The possible experiment is with regards to the factors that influence energy from the Sun

The factors investigated are;

The type of material and the angle of lighting (insulation) affects the absorption of heat

The independent variable is the variable that is the cause of the effect

measured in the experiment.

It is the variable that the researcher has control over or controls and

varies during the experiment to produce the measured effect.

In the above experiment, the independent variable are either ;

The dependent variable is the variable that is under test or that is being measured.

The controlled variable is the variable that remains the same or is held

constant during the experiment and can be used as reference to

compare the dependent variable.

In the experiment, the controlled variable are either;

Learn more about independent and dependent variables here:

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Answer:

angle of light

temperature of material

type of material

Explanation:

E d g e 22 !

Answer: 10 times more

Explanation:

Answer:

53.491 g/mol

Explanation:

Create the chemical compound and find each individual element's molar mass. Lastly, add them up.

Answer:7/10

Explanation:multiply top and bottom

Answer:

The amount of energy released from the combustion of 2 moles of methae is 1,605.08 kJ/mol

Explanation:

The chemical reaction of the combustion of methane is given as follows;

CH₄ (g) + 2O₂ (g) → CO₂ (g) + 2H₂O (g)

Hence, 1 mole of methane combines with 2 moles of oxygen gas to form 1 mole of carbon dioxide and 2 moles of water vapor

Where:

CH₄ (g): Hf = -74.6 kJ/mol

CO₂ (g): Hf = -393.5 kJ/mol

H₂O (g): Hf = -241.82 kJ/mol

Therefore, the combustion of 1 mole of methane releases;

-393.5 kJ/mol × 1 + 241.82 kJ/mol × 2 + 74.6 kJ/mol = -802.54 kJ/mol

Hence the combustion of 2 moles of methae will rellease;

2 × -802.54 kJ/mol or 1,605.08 kJ/mol.

Answer: answer is C

Explanation:

Just took the test

Answer: mercury

Explanation: I looked up the answer to your question.

Answer:

Mercury

Explanation:

I did this question and I got it right.

Answer:

[tex]\large \boxed{\text{21.6 L}}[/tex]

Explanation:

We must do the conversions

mass of C₆H₁₂O₆ ⟶ moles of C₆H₁₂O₆ ⟶ moles of CO₂ ⟶ volume of CO₂

We will need a chemical equation with masses and molar masses, so, let's gather all the information in one place.

Mᵣ:        180.16

         C₆H₁₂O₆ + 6O₂ ⟶ 6CO₂ + 6H₂O

m/g:      24.5

(a) Moles of C₆H₁₂O₆

[tex]\text{Moles of C$_{6}$H$_{12}$O}_{6} = \text{24.5 g C$_{6}$H$_{12}$O}_{6}\times \dfrac{\text{1 mol C$_{6}$H$_{12}$O}_{6}}{\text{180.16 g C$_{6}$H$_{12}$O}_{6}}\\\\= \text{0.1360 mol C$_{6}$H$_{12}$O}_{6}[/tex]

(b) Moles of CO₂

[tex]\text{Moles of CO}_{2} =\text{0.1360 mol C$_{6}$H$_{12}$O}_{6} \times \dfrac{\text{6 mol CO}_{2}}{\text{1 mol C$_{6}$H$_{12}$O}_{6}} = \text{0.8159 mol CO}_{2}[/tex]

(c) Volume of CO₂

We can use the Ideal Gas Law.

pV = nRT

Data:

p = 0.960 atm

n = 0.8159 mol

T = 37  °C

(i) Convert the temperature to kelvins

T = (37 + 273.15) K= 310.15 K

(ii) Calculate the volume

[tex]\begin{array}{rcl}pV &=& nRT\\\text{0.960 atm} \times V & = & \text{0.8159 mol} \times \text{0.082 06 L}\cdot\text{atm}\cdot\text{K}^{-1}\text{mol}^{-1} \times \text{310.15 K}\\0.960V & = & \text{20.77 L}\\V & = & \textbf{21.6 L} \\\end{array}\\\text{The volume of carbon dioxide is $\large \boxed{\textbf{21.6 L}}$}[/tex]

Answer:

MRCORRECT has answered the question

Explanation:

13 electrons

So... for the element of ALUMINUM, you already know that the atomic number tells you the number of electrons. That means there are 13 electrons in a aluminum atom. you can see there are two electrons in shell one, eight in shell two, and three in shell three.

7 electrons

So... for the element of NITROGEN, you already know that the atomic number tells you the number of electrons. That means there are 7 electrons in a nitrogen atom. Looking at the picture, you can see there are two electrons in shell one and five in shell two.

Answer: The hydroxide cation (OH -) and the phosphate cation (PO 4 3-) are both polyatomic ions.

Explanation:

Answer:

OH - and PO 4 3- are both polyatomic ions

Answer:

sulfur dichloride

Explanation:

SCl2 is the chemical formula for sulfur dichloride. This compound is made of only two elements, so it is a binary compound.

there is nothing with which it can react

Explanation:

The limiting reactant(s) prevents a reaction from continuing because there is none left.

Identification of the limiting reactant makes it possible to calculate the theoretical yield of a reaction. The reason there is a limiting reactant is that elements and compounds react according to the mole ratio between them in a balanced chemical equation.

The reactant that is consumed first and limits the amount of product(s) that can be obtained is the limiting reactant. To identify the limiting reactant, calculate the number of moles of each reactant present and compare this ratio to the mole ratio of the reactants in the balanced chemical equation.

Learn more about Limiting Reactant(s) here

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#SPJ2

Answer:

There would be an increase in temperature and corresponding increase in the volume of the balloon

Explanation:

Charles law is been here

Charles law  states that the volume of a given mass of gas  is directly proportional to the temperature in Kelvin, provided that the pressure on the gas is kept constant. Mathematically Charles law can be represented thus;

V∝ T

Where V is the volume of the gas and;

T is the temperature.

Relating Charles Law to the question

From Charles law postulation, there would be an increase in volume because of the increased temperature, since our pressure is same.

organic molecules

because organic molecules does not dissociate in water

Answer:

40.078 u

Explanation:

Answer:

yo I got same question do u know it

Answer:

Lemon juice baking soda and vinegar

Explanation:

Answer:the parts of the body which is nearest to  the ground ie thier back will show discoloration

Explanation:

If the body remains at a position for long hours, the parts of the body which is nearest to  the ground can develop a skin discoloration as a result of pooling of blood in the tissues and this is called livor mortis, which tends to be permanent from 8Hours upwards.

Answer:

I believe the answer would be A

Answer:

THE ENERGY NEEDED TO BE ADDED TO RAISE THE TEMPERATURE BY 30°C IS 145, 860 J

Explanation:

The energy needed can be calculated by using the heat formula, which is;

Heat = m c ΔT

m = mass of the hydrogen =  340 g

c = specific heat capacity of hydrogen at room temperature = 14.30 J/g°C

ΔT = change in temperature = 30°C

Heat =?

So therefore,

Heat = 340 * 14.30 * 30

Heat = 145860 J

The energy needed to be added to the hydrogen to bring the mass of 340 g to an increased temperature of 30°C is 145, 860 J or 145.86kJ

The question was not well arranged above. It has been arranged in the answer below.

Question:

Leon made a study chart about human-induced changes to the environment.

Environmental Changes Caused by Humans

X Y

Results from introducing harmful substances into the environment

Example: oil spill

Results from natural areas being cleared and replaced by human development

Example: deforestation

Which headings best complete the chart?

X: Habitat Destruction

Y: Pollution

X: Long-Term Changes

Y: Short-Term Changes

X: Short-Term Changes

Y: Long-Term Changes

X: Pollution

Y: Habitat Destruction

Answer:

X: Pollution

Y: Habitat Destruction

Explanation:

From the above question, Leon gave us two variables, X and Y.

The human induced changes were divided into two.

1. Results from introducing harmful substances into the environment

Introducing harmful substances into the environment is also called pollution. And we can represent this as X which is the first variable.

2. Results from natural areas being cleared and replaced by human development.

This description given in number two above whereby land areas are been cleared and replaced by human development has a negative effects on the environment because the vegetation which includes the trees are been cut down and living organisms(animals) will go extinct gradually. This act affect the balance of the ecosystem and it can be referred to as the destruction of the habitat of living organisms

Therefore, the correct headings best complete the chart is :

X: Pollution

Y: Habitat Destruction

Answer:

what the top person said

Explanation:

☺

Answer:

the answer is 383.0

hope it is helpful

Answer:

kmno4 is heated => k2mno4 + mno2 + o2

Hope this helps!

:)