A chemical reaction takes place to allow instant cold packs to absorb energy. This is an example of a(n) __________.
A. physical change
B. exothermic reaction
C. endothermic reaction
D. precipitate

Answers

Answer 1

Answer:

c. Endothermic

Explanation:

endothermic reactions absorb heat, exothermic reactions release heat.


Related Questions

Decreasing the volume of a gas increases the pressure of the gas. .

Answers

Answer:

False.

Explanation:

If the gas is leaving it cannot have higher pressure.

How do ionic bonds differ from covalent bonds?


Protons are transferred in an ionic bond.


Protons are shared in an ionic bond.


Electrons are shared in an ionic bond.


Electrons are transferred in an ionic bond.

Answers

Answer:

Electrons are transferred in an iconic bond.

What is a term for the forces that two objects exert on each other?

Answers

Answer:

action-reaction force.

Explanation:

the pair of opposite but equal forces that two objects exert on each other. weight. the gravitational force exerted by a large body, usually Earth, on an object.

Answer:

exerted forces

Explanation:When an object has several forces acting on it, the effects of force is same as one force acting on the object in a certain direction and this overall force is called the ‘resultant force’.

____is the terrestrial planet that has almost no atmosphere

Answers

Answer:

Should be Mercury.

Explanation:

The atmospheres of the terrestrial planets range from thin to thick. Mercury has almost no atmosphere.

what is the form of
energy that
refers to the
motion of
particles

Answers

The energy associated with the motion of particles in a substance is called average kinetic energy.

Can someone please help me I really need help

Answers

Answer:

atoms from different elements

Moleculars are made of two or more atoms

the food into energy for her muscles? *
O thermal
O physical
O chemical

Answers

Answer:

chemical

Creatine Phosphate (with oxygen) So all muscle cells contain a high-energy compound called creatine phosphate which is broken down to make more ATP quickly. Creatine phosphate can supply the energy needs of a working muscle at a very high rate, but only for about 8–10 seconds.adenosine triphosphate (ATP)

The source of energy that is used to power the movement of contraction in working muscles is adenosine triphosphate (ATP) – the body's biochemical way to store and transport energy. However, ATP is not stored to a great extent in cells

When vinegar, an acid, is mixed with baking soda, a base, the reaction is similar to the reaction of Alka-Seltzer and water; a salt, water and carbon dioxide are produced. In two or more complete sentences, describe how your knowledge of balancing chemical equations can help you to determine the missing compound. Write your answer in the essay box below. NaHCO3 + HC2H3O2 ⟶ ________ + H2O + CO2

Answers

Answer:

no.

Explanation:

you're prolly wondering why cuz this is revenge for your little game you did to me and whoops! i don't know the answer :) !

1. Which one of the following best describe sublimation?

A. A solid melting to a liquid which re solidifies.

B. A solid melting to a liquid which evaporates, the vapor condensing to a liquid and then recrystallizing.



C. The movement of gaseous particles so that they fill the spaces that they occupy.

D. A solid forming a vapor on heating and reforming as a solid on cooling.

E. The bombardment of large molecules by small molecules.

Answers

D. Sublimation is a solid turning directly into a gas

Answer:

i think it is D.

Explanation:

The answer is D because it’s where a solid turns to a gas without going through a liquid phase if that makes sense

the closeness of a measurement to its actual value is a measure of its


A. usefulness
B. reproducibility
C. precision
D. accuracy

Answers

The answer is letter D

what is the density of a man​

Answers

Answer:

1.0 g per cubic centimeter.

Explanation:

The density of a man is 985 kg/m3

A 6-mile wide meteorite hit the earth 65 million years ago. Scientists have found a high concentration of iridium in the sedimentary clay layer from this time period. Iridium is very rare in Earth’s crust, but it is abundant in meteorites. Scientists believe this impact caused the extinction of the dinosaurs. Which of these statements correctly describes whether this is a theory or a law and why?


A. It is a law, because it includes a numerical analysis.


B. It is a law, because it explains all causes of animal extinction.


C. It is a theory, because it explains the cause of the dinosaur extinction.


D. It is a theory, because it shows regular patterns from a generalization of the data.

Answers

C. It’s a theory because it wasn’t really given a law .

What are the total balance electrons?
PHOTO ABOVE

Answers

Answer: H2O has 8 electrons, GeBr4 has 32 electrons, and RbHO has 37 electrons.

Hope this helped! :)

A graduated cylinder is filled with 50.7 mL of water. If a 10.0 g piece of zinc metal is added to the water, and the volume rises to 52.1 mL, what is the density of the metal?

Answers

Answer:

The answer is 7.14 g/mL

Explanation:

The density of a substance can be found by using the formula

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

From the question

mass = 10 g

volume = final volume of water - initial volume of water

volume = 52.1 - 50.7 = 1.4 mL

We have

[tex]density = \frac{10}{1.4} \\ = 7.142857...[/tex]

We have the final answer as

7.14 g/mL

Hope this helps you

What is the kinetic energy of a 2kg rabbit hopping at a speed of 1.25 m/s

Answers

Answer:

What is the kinetic energy of a 2kg rabbit hopping at a speed of 1.25 m/s?1,5625J

Which‌ ‌of‌ ‌the‌ ‌following‌ ‌best‌ ‌describes‌ ‌an‌ ‌electron?‌ ‌

A. It‌ ‌has‌ ‌no‌ ‌charge‌ ‌and‌ ‌about‌ ‌the‌ ‌same‌ ‌mass‌ ‌as‌ ‌a‌ ‌proton.‌ ‌

B. ‌It‌ ‌has‌ ‌a‌ ‌negative‌ ‌charge‌ ‌and‌ ‌much‌ ‌less‌ ‌mass‌ ‌than‌ ‌a‌ ‌proton.‌

C.‌It‌ ‌has‌ ‌a‌ ‌positive‌ ‌charge‌ ‌and‌ ‌much‌ ‌more‌ ‌mass‌ ‌than‌ ‌a‌ ‌neutron.‌ ‌



D.‌It‌ ‌has‌ ‌a‌ ‌negative‌ ‌charge‌ ‌and‌ ‌about‌ ‌the‌ ‌same‌ ‌mass‌ ‌as‌ ‌a‌ ‌neutron.‌

Answers

Answer:

It's D. because it has negative charge and same mass as neutrons

To find out if the height from which a student drops a ball affects how high the ball bounces, the independent variable is the

Answers

Answer:

The independent variable is the height of the ball that bounces.

Question 9/10
As a boulder rolls from the top of a hill to the bottom, how does its potential and kinetic energy change?
A. Potential and kinetic energy both increase.
B. Potential increases and kinetic decreases.
C. Potential decreases and kinetic increases.
D. Potential and kinetic energy both decrease.
please help quickly

Answers

c. Potential decreases and kinetic increases.

Explanation:

As the boulder is rolling down the hill, potential energy decreases as kinetic energy increases.

_________energy is stored in chemical bonds.

Answers

Answer:

Chemical energy is the potential energy stored in the arrangement of atoms within molecules. Breaking chemical bonds requires energy, while forming new chemical bonds releases energy. The more energy that's released when a bond forms, the more stable that bond is.

Explanation:

Pleaseeee help neeeeee

Answers

The first one because if the mirror remained hot the water droplets would not be there.

Answer:

B

Explanation:

Condensation happen when water is warmed up in room temperature against a cold surface like water vapor

Which type of reaction has will give brainliest to first correct answer

the general formula of AB + CD → AD + CB?
ОООО
synthesis
decomposition
oxidation
replacement

Answers

Answer:

I think it's replacement because the B and D just swap places in the end equation

Answer:

that would be replacment

Explanation:

if you look at the formula the B and D are replaced with each other

synthesis is when it looks like A+B--> AB

decompositions looks like AB--> A+B

and oxydation is when the states of atoms are changed so it would include things like +1, -1 etc

A particle that orbits the nucleus in an atom is called a(n)

electron

proton

neutron

Answers

The answer is electron

Calculate the density of a piece of mass of metal. The rectangular piece of solid metal has the measures of 2.0 cm 3.0 cm in 2.0 is the unidentified
metal has a mass of 40

Answers

Answer:

Density = (3.33kg or g)/cm³(since you didn't state the unit of the mass)

Explanation:

volume = length × breath × height

let's take it as,

length = 2.0cm

breath = 3.0 cm

height = 2.0 cm

mass = 40 kg or g (since you didn't state the unit of the mass)

volume = ?

volume = length × breath × height

volume = (2 × 3 × 2)cm

volume = 12 cm³

Density = mass /volume

40kg or g/12cm³

Density = (3.33kg or g)/cm³(since you didn't state the unit of the mass)

Question 4(5 points)

(01.07 MC)

A student compares the boiling point of substances having different intermolecular forces. Which independent variable did the student most

likely use? (5 points)

Ob

Various compounds made of different forces between molecules

Type of source used to heat up the substances

Type of container used for the substances

Boiling points of various substances

Od

Answers

Answer:

Various compounds made of different forces between molecules

Explanation:

In an experiment, the independent variable is the variable that is changed or manipulated by the experimenter in order to effect a measurable response.

According to this question, a student compares the boiling point of substances having different intermolecular forces. This means that the student uses different substances with different intermolecular forces and measures the boiling point of each, which depends on the intermolecular forced in them. Hence, the independent variable in this experiment is the VARIOUS COMPOUNDS MADE OF DIFFERENT FORCES BETWEEN MOLECULES.

Please help, and can you tell, if some my answers are correct?

Answers

Renewable energy Environment Nutrition SunNon renewable Exhibit Environmental Science Respond React Natural resources

The difference in the direction is caused by the ______________.Please help!

Answers

What don’t understand question

PLEASEEE HELPPP!!!! AND EXPLAIN PLS

Answers

Answer: True?

Explanation: THere is no question but I do know that is true because I answers that on a test and got it right. It was asking about:

how many Helium and oxygen molecules = H2O = + O2

When ammonium chloride is dissolved in water, the beaker gets cold. Which type of reaction does this describe
O exothermic
O endothermic
O both exothermic and endothermic
O neither exothermic nor endothermic

Answers

Answer:

B

Explanation:

i think with exothermic reactions heat is released

this is what i looked up

hope this helps i took chem last year and think this is what i learned

Considering the definition of exothermic and endothermic reactions, the correct answer is second option: the reaction is endothermic.

Energy and chemical reactions

Energy is the ability to do work or to produce heat.

Remembering that chemical reactions involve a reorganization of atoms between substances with breaking or formation of chemical bonds, this formation or breaking of chemical bonds is accompanied by changes in the energy of the system.

Exothermic reactions

Chemical reactions that release heat are called exothermic. That is, an exothermic reaction is one where energy flows out of the system.

So, at room temperature, the heat released by a chemical reaction is enough to cause a rise in temperature.

Endothermic reactions

An endothermic reaction is one that requires heat to take place. In other words, a chemical reaction is endothermic when it absorbs energy from the environment.

In this case, the heat is transferred from the outside to the inside of the system. By absorbing heat, the effect of an endothermic reaction is to lower the temperature.

This case

When ammonium chloride is dissolved in water, the beaker gets cold. That means the system is absorbing heat from the surrounding and the temperature does down.

So, the correct answer is second option: the reaction is endothermic.

Learn more about endothermic and exothermic reactions:

https://brainly.com/question/4345448?referrer=searchResultshttps://brainly.com/question/11753370?referrer=searchResultshttps://brainly.com/question/18523044?referrer=searchResultshttps://brainly.com/question/9799465?referrer=searchResultshttps://brainly.com/question/4364765?referrer=searchResults

Assess It!
#4
Which two elements are
most likely to bond with
each other?
A. Oxygen and Boron
B. Nitrogen and 3 atoms of
Hydrogen
C. Chlorine and Calcium
D. Neon and Sodium

Answers

Answer:

c

Explanation:

i hope this helps

The two chemical elements that are most likely to bond with each other are: C. Chlorine and Calcium.

A chemical bond refers to the forces of attraction existing between ions, crystals, atoms or molecules and that are typically responsible for the formation of new chemical compounds.

In Chemistry, there are three (3) main types of chemical bonds and these are:

I. Hydrogen bonds.

II. Covalent bonds.

III. Ionic bonds.

An ionic bond can be defined as a chemical bond which involves a metallic element transferring one or more electrons to a non-metallic element.

In this scenario, the element Chlorine which have seven valence electrons would accept an electron from Calcium (Alkali metal) to form a chemical compound called calcium chloride.

In conclusion, two chemical elements that are most likely to bond with each other by forming an ionic bond are Chlorine and Calcium.

Read more: https://brainly.com/question/24605723

will someone help me, please

Answers

Answer:

c makes sense

Explanation:

if your just sitting there looking at it melt, thats not helping

Answer:

A

Explanation:

Different sizes of ice cubes will result in different lengths of time in staying solid. A bigger ice cube will stay solid for longer than a smaller one.

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