Which of the following is an example of a chemical change?


A. Boiling water
B. Burning paper
C. Dissolving sugar in water
D. Melting gold​

Answer:

1 Sodium, 1 Aluminum (1 Sulfur, 4 Oxygen)

Explanation:

hope that helps

Answer:

The level of CO2 in the blood is detected by chemoreceptors located in the aortic arch

and carotid arteries. These send impulses to either the cardioaccelerator or

cardioinhibitor center in the hypothalamus of the brain, which in turn sends an

impulse to the pacemaker of the heart to increase or decrease heart rate. Draw a

feedback diagram to illustrate what happens to restore homeostasis when blood CO2

rises.

Explanation:

The level of CO2 in the blood is detected by chemoreceptors located in the aortic arch

and carotid arteries. These send impulses to either the cardioaccelerator or

cardioinhibitor center in the hypothalamus of the brain, which in turn sends an

impulse to the pacemaker of the heart to increase or decrease heart rate. Draw a

feedback diagram to illustrate what happens to restore homeostasis when blood CO2

rises.

Answer:

NH₄NO₃

Explanation:

In salt naming, the cation is named first, then you must put the name of the anion. In the same way when you are writting the formula. Also, the global charge of a salt is always 0.

Thus, we must write each ion and its charge:

Ammonium: NH₄⁺

Nitrate: NO₃⁻

As both ions have the same charge, the formula is:

The cation first and then the anion.

Answer:

784.4kg

Explanation:

Given parameters:

Mass of Mg  = 200kg

Unknown:

Mass of MgCl₂  = ?

Solution:

  The reaction equation is given as:

            Mg  +  Cl₂ →   MgCl₂

Find the number of moles of the given specie;

  Number of moles of Mg = [tex]\frac{mass}{molar mass}[/tex]   = [tex]\frac{200000}{24.3}[/tex]   = 8230.5mole

So;

   1 mole of Mg will produce 1 mole of MgCl₂

   8230.5mole of Mg will produce 8230.5mole of MgCl₂

Mass of MgCl₂   = number of moles x molar mass

                    Molar mass of MgCl₂  = 24.3 + 2(35.5) = 95.3g/mol

 Mass of MgCl₂   = 8230.5mole x  95.3g/mol  = 784.4kg

Answer:

the paper could be burn up

Answer:

Okay, Left top= waning gibbous

left second= new moon

left third= third quarter

left fourth= waxing crescent

right top= Waning crescent

right second= first quarter

right third= full moon

right fourth= Waxing gibbous

hope you do good :)

Answer:

first one waining gibbious

secound one waining crecent

third one new moon

fourth one first quarter

fithe one third quarter

sixth one  full moon

sevnth one waxing crecent

eithe one waxing gibbious

Explanation:

In liquid state, the temperature will be 0°C.

D. Liquid

Jet fuels are colorless liquids.

These are colorless liquids that are flammable and smell like kerosene. The fuels are made from chemical compounds called hydrocarbons, which are found naturally in the earth as crude oil. In order for gasoline to freeze it needs to be held at temperatures of around -100 degrees F. Jet fuel cools at the rate of around 3°C per hour, faster in very cold climates.

Thus, correct option is d.

Find more information about Jet fuel here:brainly.com/question/26597375

But, an irregular surface, for every bump, the light bounces down up down up down up.

I hope this helped! +*♡

Answer:

He was having a tough time as his mother abandoned him at the age of three or we can say his mother passed which led to his insecurity.

1.43 × 10⁻²⁰ mol Li

Math

Pre-Algebra

Order of Operations: BPEMDAS

Chemistry

Atomic Structure

Step 1: Define

8.63 × 10³ atoms Li

Step 2: Identify Conversions

Avogadro's Number

Step 3: Convert

Step 4: Check

Follow sig fig rules and round. We are given 3 sig figs.

1.43355 × 10⁻²⁰ mol Li ≈ 1.43 × 10⁻²⁰ mol Li

The Δ Hrxn, in kJ/mol, for this reaction= 11.04 kJ/mol

Given

0.848 g ammonium nitrate

The enthalpy change : +0.117 kJ

Required

Δ Hrxn, in kJ/mol

Solution

Delta H reaction (ΔH) is the amount of heat change between the system and its environment  

The value of ° H ° can be calculated from the change in enthalpy of standard formation:  

∆H ° rxn = ∑n ∆Hf ° (product) - ∑n ∆Hf ° (reactants)  

mass of NH4NO3 = 0.848 g

mol of NH4NO3(MW = 80 g/mol)

mol = 0.848 : 80

mol = 0.0106

The Δ Hrxn :

= 0.117 kJ : 0.0106 mol

= 11.04 kJ/mol

Answer:

Van der Waals forces is defined as the force that include attraction and repulsions between atoms or molecules, and also involve intermolecular forces

Vander Waals force formed between the similar molecules and not different molecules, that means Van der Waals force  exist between two water molecules and not between hydrogen and oxygen of one molecule. Hydrogen and oxygen are connected with covalent bonds.

Answer:

Each time an excited helium atom falls back from an excited state to its ground state or to a lower energy state, it emits a photon of radiation that shows up as this specific line-emission spectrum.

Explanation:

Answer:

the third one because oceans don't affect the weather  

Explanation:

Answer:

I'm pretty sure its liver and pancreas

Explanation:

the pancreas delivers the digestive juice to the small intestine through small tubes, your liver makes the digestive juices called the bile that helps digest fats and some vitamins

Answer:

the answer is liver and pancreas

Answer:

720 pencils

Explanation:

The parameter given are;

The unit quantity by which the pencils are sold = 1 gross

The number of pencils Daffodil orders = 5 gross of pencils

One gross is a quantity equal to twelve dozens

Therefore, we can write;

1 gross = 12 × 12 = 144

From which we have;

5 gross = 5 × 144 = 720

Which gives;

For the 5 gross of pencils Daffodil orders, she receives 720 pencils

Answer: first is last second is first and 3rd is second

Explanation:

1. 4

2. 4

3. 2

4. 2

Given

Reaction

2H₂+O₂⇒2H₂O

Required

Number of atoms

Solution

In compounds, the number of atoms of the constituent components in the form of elements is usually indicated by a subscript after the element symbol, while the number in front of the compound which is the coefficient indicates the number of molecules of the compound.

In chemical reactions, the reactants are on the left and the products on the right

1. Number of Hydrogen in reactants

2 molecules x 2 atoms = 4 atoms

2. Number of Hydrogen in products

2 molecules x 2 atoms = 4 atoms

3. Number of Oxygen in reactants

1 molecules x 2 atoms = 2 atoms

3. Number of Oxygen in products

2 molecules x 1 atoms = 2 atoms

The reaction is said to be balanced because the number of atoms of the element is the same between the reactants and products

Answer:

1. 4 km

2. 40 minutes

3. 5 minutes for each km

rlly hope this helps:)

Answer:The height of First Copy is 20 cm.

Step-by-step explanation:

Given:

Original Height = 25 cm

First copy is reduce to 80% of Original height.

Therefore to find the height of first copy can be find out by multiplying 80 with original height and then dividing by 100.

∴ Height of First Copy =

Hence Height of first copy is 20 cm

Now Another copy is reduce to 85% of First Copy.

Therefore to find the height of another copy can be find out by multiplying 85 with first copy height and then dividing by 100.

∴ Height of Another Copy =

Hence Height of Another copy is 17 cm

Explanation:

Answer:

How many moles H2O in 1 grams? The answer is 0.055508435061792.

We assume you are converting between moles H2O and gram.

You can view more details on each measurement unit:

molecular weight of H2O or grams

This compound is also known as Water or Dihydrogen Monoxide.

The SI base unit for amount of substance is the mole.

1 mole is equal to 1 moles H2O, or 18.01528 grams.

Explanation:

The mass of 4.0 moles of water is 72 grams.

Explanation:

[tex]Moles=\frac{\text{mass of substance}}{\text{molar mass of substance}}[/tex]

Given:

The 4.0 moles of water

To find:

Mass of moles of water

Solution:

The moles of water = 4.0 moles

The mass of water = M

The molar mass of water = 18.01528 g/mol

[tex]4.0=\frac{m}{ 18.01528 g/mol}\\m=4.0\times 18.01528 g/mol\\=72.06112 g\approx 72 g[/tex]

The mass of 4.0 moles of water is 72 grams.

Learn more about moles of substance here:

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Answer:

The energy transported by a wave is directly proportional to the square of the amplitude. So whatever change occurs in the amplitude, the square of that effect impacts the energy. This means that a doubling of the amplitude results in a quadrupling of the energy.

Answer:

a

Explanation:

Answer:

D

Explanation:

Answer:

Mass = 5013.36 g

Explanation:

Given data:

Number of moles of CsPO₄ = 22 mol

Mass of sample = ?

Solution:

Formula:

Mass = number of moles × molar mass

Molar mass of CsPO₄ = 132.91×1 + 30.97×1 +16×4 = 227.88 g/mol

by putting values,

Mass = 22 mol ×  227.88 g/mol

Mass = 5013.36 g

Answer:

Buffalo and Watertown.

Explanation:

This is correct as the Interior lowlands are located ib the US. These are correct as the others are in the US but aren't located anywhere near the Interior Lowlands.

Answer:

Dr. Tierno tested the pillows for signs of microorganisms. He took samples from the pillow, then he grew the microorganisms in a petri dish.

Explanation:

This is the answer on edmentum