I need help with this one please it’s science

I Need Help With This One Please Its Science

Answers

Answer 1

Answer: A change in appearance. (Please say thanks!)

Explanation:

The biggest sign of a chemical change is change in appearance.

Answer 2

Answer:

d

Explanation:


Related Questions

The reaction for the combustion of acetylene is shown. Explain why this reaction is a redox reaction by identifying the oxidation numbers that change, what is oxidized, what is reduced, and what happens to the electrons during the reaction. 2C2H2 + 5O2 → 4CO2 + 2H2O

Answers

Answer:

2 C2H2 (g) + 5 O2 (g) → 4 CO2 (g) + 2 H2O (l)

Explanation:

Redox reaction: In this type of reaction, oxidation and reduction reaction occurs simultaneously in same chemical reaction.

2C_2H_2+5O_2\rightarrow 4CO_2 + 2H_2O2C

2

H

2

+5O

2

→4CO

2

+2H

2

O

This reaction is a redox reaction :

Removal of hydrogen or addition of oxygen is termed as oxidation. in above reaction, removal hydrogen from acetylene gives carbon-dioxide.

Removal of oxygen or addition of hydrogen is termed as reduction. in above reaction, removal of one oxygen atom from oxygen molecule with addition of two hydrogen atoms gives water

The oxidation number of carbon in acetylene is -2.

The oxidation number of carbon in carbon-dioxide= +4

Oxidation number of carbon increases after the reaction which means that carbon is getting oxidized.

The oxidation number of oxygen in oxygen gas = 0

The oxidation number of oxygen in water = -2

Oxidation number of oxygen decreases after the reaction which means that oxygen is getting reduced.

The electrons released during oxidation are transferred to the species which are undergoing reduction reaction.

Answer:

Just put this, or something like it:

The oxidation number of carbon changes from -1 to +4.

The oxidation number of oxygen changes from 0 to -2.

Carbon is oxidized.

Oxygen is reduced.

Electrons are transferred from carbon to oxygen.

Explanation:

Electrons in Atoms
The (type here) of the atom is the most up-to-date model of the atom at this point.

Answers

Cloud model or Bohr Model

generally speaking, the Bohr model encapsulates the modern understanding of the atom. This model is often depicted in artwork showing a central atomic nucleus and oval lines representing the orbits of the electrons.

Bohr

Four siblings did chores during the weekend. Lin cooked eggs. Gabe raked leaves. Chris sewed buttons on a shirt. Briana dried laundry. Which of these involved a chemical change?

Answers

Answer:

Pretty sure it's A, cooked eggs (so Lin)

Answer:

A

cooking eggs :)

just did it on pf

Explanation:

:)

what information can you figure out about an atom using only the atomic number?​

Answers

the number of protons
The number of atoms

Now look closely at the patterns in the table. Compare the elements in each column and
row. What can we say about elements in the same group and elements in the same period
of the periodic table?
Select all the correct answers.
- The number of electrons in the second energy level increases by one down each
column.
Elements in the same row have the same number of ocupied energy levels.
For each column, the last occupied energy level has the same number of electrons.
The number of electrons in the first energy level increases by one from Li to Ne.

Answers

Answer:

A the first 1

Explanation:

What is the difference between a hyrdrogen atom and a hydrogen molecule?

Answers

Answer:smaller

Explanation:

Answer:

Explanation:

A hydrogen atom (H) is bonded to form hydrogen gas(H2)(a molecule)

10. A(n) eclipse occurs at a full moon when Earth is directly between the moon and the sun.​

Answers

Answer:

Yes indeed

Explanation:

Which of the following is not a controllable risk factor?
a. smoking
b. inactivity
c. aging
d. over eating

Answers

Answer:

C) Aging

Explanation:

You can't stop that or change the rate that you age at. its inevetable :D

The mass of a block is 2.5 g the volume of the block is 4.1 mL.  what is the density of the block

Answers

Answer:

6.6g

Explanation:

(100 points) Atleast 5 slogans on saving fuel.

Answers

Answer:

Save Fuel, Save Earth

Fuel and time wait for none!

Be wise, don’t waste fuel

Save fuel, stop being cruel

Don’t contribute towards global warming

Care for future, save fuel

Hope That Helps!!!

Explanation:

Here are Best Slogans on Save Fuel.

-Towards a better future.

-Save to sustain.

-Save fuel for a better world.

-Make sure to keep some for the next generation.

-Our resources are limited.

-Save to expand.

-Saving fuel has no alternatives.

-Save money while saving fuels.

what are green boxes on periodic tables

Answers

Answer:

The basic metal ones?

Explanation:

...

If the mass is 7150 kg, and the
acceleration is 2 m/s2, then what is the
force?

Answers

Explanation:

f= ma

f= 7150 *2

f= 14300N

The force will be equal to 14300N when the mass is 7150 kg and the

acceleration is 2m/s².

What is force?

Force is an external agent that can change a body’s state of rest or motion. Force has a direction and a magnitude so it is a vector quantity. The SI unit of force is Newton and the unit used is Kgm/s².

Force can change the state of a body from rest to motion and can accelerate the speed of a moving body.  The direction of a moving object can be changed by applying force.

The force is expressed by the product of the mass (m) and acceleration (a) of an object. The mathematical equation for force can be expressed in the form of:

F = ma

Given, the mass (m) = 7150 Kg and acceleration (a) = 2 m/s²

Then, force, F = (7150 Kg) × (2 m/s²)

F = 14300 Kgm/s²

or, F = 14300 N

Therefore, the force of the object will be equal to 14300 N.

Learn more about force, here:

https://brainly.com/question/13191643

#SPJ2

what further observation led mendeleev to create the periodic table

Answers

Answer:

;,knbbbknnbkhbln bhbj k; b; m j

Explanation:

Which is composed of aromatic hydrocarbons?
clothing
barbeque fuel
pain relievers
O polyvinyl chloride

Answers

Answer:

the answer is pain relievers

Which is composed of aromatic hydrocarbons?

clothing

barbeque fuel

pain relievers

polyvinyl chloride

Pain relievers are composed of aromatic hydrocarbons. Therefore, option C is correct.

What are aromatic hydrocarbons ?

Hydrocarbons with delocalized pi electrons and sigma bonds between their carbon atoms are known as aromatic hydrocarbons. One example is benzene. Since they smell, they are said to as aromatic.

One aromatic ring makes up monocyclic aromatic hydrocarbons (MAHs). The well-known environmental contaminants benzene, toluene, ethylbenzene, and xylenes are among the most combustible and water-soluble aromatic hydrocarbons (BTEX).

The typical aromatic parent structure is benzene. When the benzene ring is a substituent, it is referred to as a phenyl group.

Thus, Pain relievers are make up of aromatic hydrocarbons, option C is correct.

To learn more about an aromatic hydrocarbon, follow the link;

https://brainly.com/question/3614247

#SPJ6

Suppose that green spheres represent chlorine atoms, yellow-green spheres represent fluorine atoms, white spheres represent hydrogen atoms, and all the molecules are gases

Answers

Answer:

a. Reactants: F₂ and HCl molecules

Products: Cl₂ and HF

b. 4HCl + 2F₂ ----> 4HF + 2Cl₂

c. Single replacement reaction

Note: The question is not complete. The complete question is found below as well as in the attachment.

Suppose that green spheres represent chlorine atoms, yellow-green spheres represent fluorine atoms, white spheres represent hydrogen atoms, and all the molecules are gases:

a. write a formula for each of the reactants

b. write a balanced equation for the reaction

c. indicate the type of reaction as combination,decomposition, single replacement, double replacement, or combustion

Explanation:

a. From the models shown in the diagram, The reactants are F₂, HCl while the products are Cl₂ and HF respectively

b. Equation for the reaction is given below;

4HCl + 2F₂ ----> 4HF + 2Cl₂

c. The reaction is single replacement reaction such that fluorine gas molecules replace the chlorine atoms in hydrogen chloride to form hydrogen fluoride with the liberation of chlorine atoms as gaseous molecules.

scientists studying squirrels in a forest observed that the squirrel population decrease over a period of five years. which statement is the most likely explanation for the decrease in the population?​

Answers

Answer:

1.An increment of predators

2.unavailability of food resources due to change in climate causing famine

3.Spread of diseases over time that might kill the squirrels

4.An increment of squirrels which caused high competition on food,thus some of them had to migrate

5.Might be fire break out over some time that caused death to some squirrels in the reasoning of the period of time

I have the coldest temperature of the atmosphere. Who am I?

Answers

Answer:

Jack Frost of course!!!!!!!

The density of water is 1.00 g/mL. Which substance below can float on water?

Answers

Answer:

ice, air, ducks and fabric

Explanation:

its common sense

Which family of elements has six electrons in d-type orbitals?

Answers

Answer: Selenium is a member of the sulfur family with elements including tellurium and polonium. This family has six electrons in the outermost shell. Selenium specifically has an electron configuration of 2-8-18-6. The six electrons in the outermost shell allow selenium to have a variety of valence numbers.

Explanation:

i need this ASAP i will give brainliest :)



Which term is defined as the ratio of the speed of light in a vacuum to the speed of light in the material it is passing through?

Answers

Answer:

I really dont know i just guessed :(

Explanation:

Answer:

index of refraction

Explanation:

What happens to the dry ice after sometime? ​

Answers

Answer:

As a rough rule, five pounds of dry ice will turn from a solid to a gas in 24 hours. It's best to pick up the block of ice just a few hours before your party so it's as frozen as possible when the bash starts.

Explanation:

Could cellular respiration
happen without photosynthesis? Explain your
reasoning

Answers

Answer:

No

Explanation:

Without photosynthesis, there would be no sugar, without which there could be no cellular respiration.Both animal cells and plant cells depend on cellular respiration for their energy needs, because both animal cells and plant cells need ATP.

Calcium nitrate and calcium carbonate are both ionic compounds.

Calcium nitrate mixed with water behaves as an electrolyte.

Calcium carbonate mixed with water does not behave as an electrolyte.

Explain, in terms of solubility and movement of ions, this difference in behaviour​

Answers

Answer:

Calcium nitrate is soluble in water and dissociate into ions whereas calcium carbonate is insoluble and water and do not form ions.

Explanation:

An electrolyte is a substance which conducts electricity in molten form or when dissolved in water.

The ability of an electrolyte to conduct electricity is due the movement of charged particles called ions. The ions are of two types: negatively charged ions called anions and positively charged ions called cations.

Calcium nitrate is a soluble in water, and when dissolved in water produces two ions; negatively charged nitrate ions,NO₃⁻, and positively charged calcium ions, Ca²⁺. These ions enable it to conduct electricity.

Calcium carbonate on the other hand is insoluble in water, and thus, do not produces any ions capable of carrying current.

3. How are the protons held in the
nucleus?
O opposite charges
O strong nuclear force from neutrons
Owhich nuclear wall

Answers

They are help together by the strong nuclear force from neutrons

8.
Blank is the transfer of energy by electromagnetic waves.
Your answer

Answers

electromagnetic radiation.




what is the formula for dihydrogen tetraoxide

Answers

It's been a while... but I'm pretty sure it's

H₂O₄

4 Identify What are the starting materials
and products of photosynthesis and cellular
respiration?

Answers

Answer:

Detail is given below.

Explanation:

Photosynthesis:

Reactants =   Carbon dioxide + water + energy

Products =    glucose + oxygen

Chemical equation:

6H₂O + 6CO₂ + energy  →   C₆H₁₂O₆ + 6O₂

It is the process in which in the presence of sun light and chlorophyll by using carbon dioxide and water plants produce the oxygen and glucose.

water is supplied through the roots, carbon dioxide collected through stomata and sun light is capture  by chloroplast.

Cellular respiration:

Reactants =  Glucose + oxygen

Products =  carbon dioxide + water + 38ATP

Chemical equation:

Glucose + oxygen → carbon dioxide + water + 38ATP

It is the breakdown of glucose molecule in the presence of oxygen to yield large amount of energy. Water and carbon dioxide are also produced as a byproduct.

Tendency of an object to float

Answers

Answer:

Buoyancy is the ability or tendency of an object to float in a fluid: a liquid or a gas. This happens because fluid pressure increases with depth. According to Archimedes' Principle, the buoyant force on a submerged object is equal to the weight of the liquid displaced by the object.

Explanation:

Isopentyl acetate is the molecule largely responsible for the aroma and taste of bananas. It is made up of carbon, hydrogen, and oxygen. Combustion of a 3.256-g sample of isopentyl acetate produces 7.706 g CO2 and 3.156 g H2O. Using these results, what is the correct empirical formula for isopentyl acetate?

Answers

Answer:

Explanation:

7.706 g of CO₂ will contain 12 x 7.706 / 44 g of C

= 2.1 g of C .

This will be contained in 3.256 g of isopentyl acetate

3.156 g of H₂O will contain 2 x 3.156 / 18 g of H

= .351 g of H

This will be contained in 3.256 g of isopentyl acetate

Rest will be oxygen

amount of oxygen in 3.256 g of isopentyl acetate

= 3.256 - ( 2.1 + .351 )

= .805 g

ratio of C , H , O in isopentyl acetate

= 2.1 g : .351 g : .805 g

2.1 / 12 : .351 / 1 : 0.805 / 16 ratio of moles

= .175 : .351 : .05  ratio of moles

= 3.5 : 7.02: 1

= 7 : 14 : 2

empirical formula of  isopentyl acetate

= C₇ H₁₄ O₂ .

The tendency of an atom to attract electrons to itself is ionization energy. effective nuclear charge. electron affinity. electronegativity.

Answers

Answer:

electronegativity

Explanation:

Answer:

THe tendoncy is electronegstivity

Explanation:

Im a big brain person

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