which is evidence that a chemical reaction has occurred?

a. a phase change occurs

b. a new gas is observed in the form
of bubbles

c. red and yellow paint mixing to make orange paint

d. the temperature of the substances remains constant

Answers

Answer 1

Answer:

b. a new gas is observed in the form  of bubbles

Explanation:

The only statement that was evidence of a chemical reaction is a new gas is observed in the form of bubbles Any time a new substance is created, a chemical reaction has taken place.


Related Questions

*BRAINLIEST BRAINLIEST
Which wavelength would have the highest energy?

670 nanometers

1.3x10^-10 meters

5.3x10^-8 meters

1.5x10^-3 meters

Answers

Answer:

THE 3 third one

Explanation:

What can we do with even more scientific knowledge?

Answers

Explanation:

Scientific knowledge allows us to develop new technologies, solve practical problems, and make informed decisions, both individually and collectively.

Answer:

If we had more scientific knowledge, we would be able to increase the productivity of life-saving equipment that provides a longer life for us

be able to make more sensible and informed decisions

make more achievements in studies and be more accurate etc..

Hope this helps<3

How many grams of potassium nitrate are produced when 3.0 grams of
potassium phosphate reacts with excess grams of aluminum nitrate?
Answer 4.2 g. *

Answers

the answer is 4.2 grams

I NEED HELP RN 40 POINTS

Answers

Answer:

B.) Adding a source of carbon dioxide to the water.

Explanation:

I had that question too.

What effects do winds patterns have on climate

Answers

Prevailing winds bring air from one type of climate to another. For example, warm winds that travel over water tend to collect moisture as they travel; the water vapor in the air will condense as it moves into colder climates, which is why temperate coastal areas often receive heavy rainfall.

Hope it Helps! T^T

Which of the following best describes the relationship between the speed of sound and the type of medium?

A.
Sound travels slower in air because of the large distance between air particles

B.
Sound travels slower in solids because of the small distance between solid particles

C.
Sound travels slower in air because of the small distance between air particles

D.
Sound travels slower in solids because of the large distance between solid particles

Answers

Answer:

A.  Sound travels slower in air because of the large distance between air particles

Explanation:

Sound is a mechanical wave that requires a medium for its propagation. Without a medium, sound cannot go through easily or readily. This implies that sound cannot be propagated through a vacuum.

A vacuum is an empty space without any particles in side. Sound waves travel fastest the most in solids because the particles are dense and close to one another. The speed of sound in air is the least because of the large distance between air particles. Therefore, the speed of sound is medium dependent

What is the energy of a photon that emits a light of frequency 7.21 x 1014 Hz? A. 4.78 x 10-19 J B. 2.76 x 10-19 C. 1.0910-19 J D. 4.16 x 10-19 J​

Answers

Answer:

E = 4.78×10^−19 J

Explanation:

The chemical equation for the energy of a photon is given by:

E =hν , where h is the Planck constant and ν is the frequency.

E =hν = 6.626×10^−34 Js × 7.21×10^ 14

s−1 = 4.78 × 10^−19 J

Answer:

A. 4.78 x 10-19 J

Explanation:

A P E X

1. What processes change sediments into a sedimentary rock?

Answers

For sediments to become a sedimentary rock, it usually undergoes burial, compaction, and cementation. (Hope that helps)

need answer ASAP

If 20.0g of water at 56.2°C absorbs 195 J of heat, what is the final temperature?
^in degrees celsius

What mass of water would increase in temperature from 45.0°C to 98.0°C after
absorbing 6830 J of energy?
^IN GRAMS

Answers

Answer:

1. 58.5°C = Final temperature

2. Mass of water = 30.8g

Explanation:

The general equation of specific heat of a substance is:

Q = C*m*ΔT

Where Q is the heat involved in Joules,

C is specific heat (Water = 4.184J/g°C),

m is mass of substance,

ΔT is change in temperature (Final temperature - Initial temperature)

For the first problem:

1. 195J = 4.184J/g°C*20.0g*ΔT

ΔT = 2.3°C = Final T - Initial T

ΔT = 2.3°C + 56.2°C =

58.5°C = Final temperature

In the seconf problem:

2. 6830J = 4.184J/g°C*m*(98.0°C-45.0°C)

6830J / 4.184J/g°C*53°C = m

30.8g = m

Mass of water = 30.8g

Identify two reasons why the relative size of an atom become smaller due to the loss of electrons .

Answers

Answer:

nucleus as electrons are being added to the same principal energy level. These electrons are gradually pulled closer to the nucleus because of its increased positive charge. Since the force of attraction between nuclei and electrons increases, the size of the atoms decreases.

Explanation:

Nuclear attractive pull to the electrons results in smaller atomic radius. Two reasons that leads the size of an atom smaller by electron loss are nuclear pulling and emptying outermost orbital.

Why atomic radius reduces by electron loss?

The nucleus have a net positive charge and electrons are negative in charge, thus, each electron experience a nuclear attractive pull. However, each electrons are shielded slightly from this attraction by the surrounding electrons.

The reasons which make the atomic radius smaller are the following.

By losing electrons the total number of electron is reducing therefore, the screening or shielding of an electron by other electron from the nuclear attractive pulling reduces, and thus due to the nuclear attraction, the orbitals shrinks inwards and reduces the atomic size. By losing electron from the outermost orbital if it contains only one electron then the orbital becomes empty and the atomic radius shrinks to the penultimate shell or orbital.

Therefore, due the two reasons mentioned above, the atomic radius reduces by electron loss.

To learn more about atomic size, refer the link below:

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What is the density of a block with a volume of 5 cm3 and a mass of 20 g?​

Answers

Answer: 4g/cm^3 or 4000g/L (4kg/L)

Explanation:

I'm not sure what units the question intended so I put both. For the first one, the equation for density is mass/volume so I divided the 20g by 5cm^3 to get 4g/cm^3. Just in case those aren't the intended units for volume and is instead liters, one cm^3 equals one ml. In addition, there are 1000ml in every liter so you can determine the amount per liter by multiplying 4g/ml by 1000 to get 4000g/L or 4kg/L.

I hope this helps.



HELP ASAP EILL MAKE BRAINLEST Students are conducting a la estimating the time takes for the cell cycle in normal chocols They find that the average time for one complete el cycle is 22 hours What arence would they expect to see nerous chien
Cancerous chicken cels will spend more time in the phase
Cancerous cells will not complete all phases of the cell cyce
Cancerus chin cells will complete moss in a shorter amount of time
O Cancerous chicken cols and normales will have the same total amount of time to complete the cell cycle

Answers

Answer: I don't know if this helps but here's some information I think might help.

Usually, cells will take between 5 and 6 hours to complete S phase. G2 is shorter, lasting only 3 to 4 hours in most cells. In sum, then, interphase generally takes between 18 and 20 hours. Mitosis, during which the cell makes preparations for and completes cell division only takes about 2 hours. Calculate the percentage of time spent in each phase by counting the total number of cells in each phase (total in interphase, in prophase, etc.) and dividing each by the total number of cells you counted. How do cancer cells differ in total time required for mitosis? Cancer cells produce 117 minutes faster than regular cells. ... Normal cells require 640 minutes during interphase, cancer cells only need 380. For prophase, cancerous cells need 15 minutes less than regular cells. Another hallmark of cancer cells is their "replicative immortality," a fancy term for the fact that they can divide many more times than a normal cell of the body. In general, human cells can go through only about 40-60 rounds of division before they lose the capacity to divide, "grow old," and eventually die 3.

How many grams of carbon are in 300 g of glucose

Answers

There is 48 grams of carbon

When a chemical change occurs:

A) the law of conservation of mass is always obeyed
B) the chemical properties of new substances are different from the ones you started with
C) all of the options are true
D) atoms are rearranged

Answers

Answer:

Are composed together

Explanation:

According to collision and transition state theories, what is the importance of activation energy?

Answers

According to the collision theory, the following criteria must be met in order for a chemical reaction to occur: Molecules must collide with sufficient energy, known as the activation energy, so that chemical bonds can break.

Could I have branliest, heart with 5 stars

Thanks and have a happy Christmas

Collision theory expresses that substance responses (in the gas stage) happen because of crashes between reactants.

Importance of activation energy:

To really start a reaction, impacts should be adequately lively (dynamic energy) to break compound bonds; this energy is known as the Activation energy. As the temperature rises, atoms move quicker and impact all the more energetically, significantly improving the probability of bond breakage upon crash.

Find more information about Activation energy here:

brainly.com/question/1380484

Diamonds are formed when carbon is placed under extreme heat and pressure. This process
in caves
in the ocean
In the atmosphere of Earth
beneath the surface of Earth,

Answers

Answer:

beneath the surface of Earth

Explanation:

Diamonds are made up of carbon that has been placed under extreme heat and pressure conditions.

These conditions of high pressure and temperature can only be found within the subsurface. As you go deeper to the mantle, the geothermal gradient rises significantly.

Also, the overburden pressure will also be high.

These processes can also occur on other planets and some can be associated to the earth times when the earth was being formed.

The condition at which diamond forms confers some of the distinct natural properties that typifies it.

How we can preserve the wetlands areas of nepal?

Answers

Answer:

Reduce, reuse, and recycle your waste and trash. Protecting the environment helps protect the wetlands, especially since trash can make its way into the water. The best and easiest way to protect the environment is by limiting your household waste.

How many electrons can fit in the sixth energy level

Answers

Answer:

72 electrons

Explanation:

The 6th shell could hold up to 2(6)² = 2(36) = 72 electrons

_FeBr3 +_H2SO4 --->_Fe2(SO4)3 +_HBr​

Answers

Answer:

2FeBr₃ + 3H₂SO₄ ⇒ Fe₂(SO₄)₃ + 6HBr

Explanation:

match the products and reactants of both sides.

how many moles of oxygen molecules can be produced from 6 moles of lead oxide

Answers

Answer:

Moles of oxygen molecules produced = 3 mol

Explanation:

Given data:

Moles of oxygen molecules produced = ?

Number of moles of lead oxide decomposed = 6 mol

Solution:

Chemical equation:

2PbO₂          →        2PbO + O₂

Now we will compare the moles of oxygen and lead oxide.

                   PbO₂        :          O₂

                      2           :            1

                      6           :           1/2×6 =3 mol

three moles of oxygen molecules are produced.

how does the understanding of electron location allow us to change the world?

Answers

Answer:

The absorbed energy will change the electron's position. We can never know both the momentum and position of an electron in an atom.

Explanation:

Please help
As the temperature increases, the molecular motion of the molecules decreases and it
becomes difficult to overcome the polar attractions.
a. TRUE
b. FALSE

Answers

true
step by step explanation:

Is a tooth made out of matter or not matter?

Answers

Human teeth are made up of four different types of tissues.

Which forms of energy are released by a burning candle? (2 points) a Light energy and chemical energy b Light energy and heat energy c Heat energy and electrical energy d Mechanical energy and heat energy

Answers

B. Light energy and heat energy!

This is because the thermal energy which is the heat. As you know fire heats up and burns, a lit candle would do just the seem. Also the fire is bright enough to light up an area!

Answer:

light and chemical energy

Explanation: mark me brainliest please

Which statement describes a neutral atom?
A. positively charged, with the number of protons greater than the number of electrons B. negatively charged, with the number of electrons greater than the number of protons C. the number of protons equaling the number of electrons, with varying numbers of neutrons
D. the number of protons equaling the number of valence electrons only

Answers

Answer:

C

Explanation:

A neutral atom always has the same number of electrons and the total number of protons.

Sodium chloride (NaCl) is formed in a chemical reaction between sodium (Na) and chlorine (Cl2).
What is sodium chloride?
14.
A.
an element
B.
a mixture
C.
a compound
D.
an atom

Answers

I think it is compound

The solids and liquids with the strongest intermolecular forces of attraction will have the
lowest melting and boiling points.
a. TRUE
b. FALSE

Answers

trueeee!!!
step by step explanation

One gram of salt in swimming pool of water could be considered a _____ solution.​

Answers

Answer:

Soluable

Explanation:

Because salt dissolves in water.. Your question has no background information to go off of

Answer:

dilute

Explanation:

trustt

Which of the diagrams below shows an atom that is not a form of hydrogen?

Answers

Answer:

I believe is the npp i kinda forgot how to do these lol

Diagram with npp type shows an atom that is not a form of hydrogen.

What is an atom?

An atom is defined as the smallest unit of matter which forms an element. Every form of matter whether solid,liquid , gas consists of atoms . Each atom has a nucleus which is composed of protons and neutrons and shells in which the electrons revolve.

The protons are positively charged and neutrons are neutral and hence the nucleus is positively charged. The electrons which revolve around the nucleus are negatively charged and hence the atom as a whole is neutral and stable due to presence of oppositely charged particles.

Atoms of the same element are similar as they have number of sub- atomic particles which on combination do not alter the chemical properties of the substances.

Learn more about atom,here:

https://brainly.com/question/30898688

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Lithium
Which statement about lithium describes what makes lithium very reactive?
F.
The number of neutrons in the nucleus.
G
The number of electrons in the first energy level.
H.
The number of protons in the nucleus.
J.
The number of electrons in the last energy level.

Answers

Answer:f

Explanation:

Other Questions
The question is in the photo Solve the system of equations by substitution. y = 2x y = x +1 The sum of two numbers is 10. The larger number is 4 times the smaller number. What are the two numbers? Let x = the smaller number. Lety = the larger number. Which two equations represent the system for this word problem? Equation 1: Equation 2: Slope : 4.Point : (-10, 30)Really need help on this please 30 POINTS ON THE LINE PLEASE HELP What do the words "rose" and "concrete" represent as used in The Rose That Grew From Concrete?Beauty and hardshipsPeople who face their fears and the things that frighten themA rose growing in the wrong placePeople who overcome struggle and the challenges they face AND IF YOU KNOW ALL THE CORRECT ANSWERS TO THE WHOLE TEST PLEASE LET ME KNOW WITH YOUR ANSWER AND I WILL MARK BRIANLEAST 3.Work in groups of five and narrate your memorable event with someexciting experiences that you had. 2/3 divided by 1/4 as a fraction! HURRY!!! How does French cuisine and eating lifestyle differ from your own? Conduct online research about the food in France. Then write a 6-8 sentence paragraph in English that summarizes what you learned. Focus on the following questions in your response:How do the types of foods eaten compare or contrast to the food that you eat in a typical day?How do mealtimes compare/contrast to your typical mealtimes?How doe the number of meals and snacks compare/contrast to your own eating habits?How do the size of meals compare/contrast to your typical meals? The Anglo settlers in Texas faced all of the following problems except:a. droughtb. Native American raidsc.loss of supplies when Lively was shipwreckedd. Mexican government would not give permission for colonization. someone help me answer this please i will mark brainliest x 8.A student measured the mass of a rubber stopper to be 6.00 grams. When it was placed into agraduated cylinder that initially had 2.0 mL of water, the water went up to the 5.0 mL of water. What isthe density of the rubber stopper?a) 3.0 g/mL b) 1.2 g/mLd) 0.60 g/mLe) none of these$) 2.0 g/mL A company reports basic earnings per share of $3.50, cash dividends per share of $1.25, and a market price per share of $64.75. The company's dividend yield equals:a. 1.93% b. 2.14% c. 4.67% I'm not smart can someone please help me...?Omar drove 420 miles using 18 gallons of gas. At this rate, how many gallons of gas would he need to drive 375 miles? if a coin is flipped 60 times and heads comes up 39 times what is the relative frequency A method which applies to the class in which it is declared as a whole and not in response to method calls on a specific object is called a:_______a. method callb. an object methodc. private methodd. static method Which phrase from the Declaration of Independence reflects theEnlighternment principle of natural rights?OA. At places unusual, uncomfortable, and distantO B. Deriving their just powers from the consent of the governedOC. The political bands which have connected them with anotherOD. Life, Liberty and the pursuit of Happiness pls help and thx WILL GIVE BRAINLIEST 5.3x3 + 2y2 - xy for x = 2 and y = 3 Tricia has $37.25 in her account. Which shows the amount she will have left after she writes a check for $23.99? A. $12.36 B. $12.74 C. $13.26 D. $13.74 Chaston began making regular deposits of a certain amount of money each month, m, starting November 1st. The function F(m) = 25 m + 200 models the amount of money in his account after he started saving money. Assuming Chaston made no purchases from the account after November 1st, which of the following is NOT true?A) Chaston made monthly deposits of 25 dollars per monthB) 2 months after he started saving Chaston would have $250 in his accountC) After 25 months of saving Chaston had $200 in his accountD) Chaston initially had $200 in his account before he began making regular monthly deposits