Why do chemical changes happen

Answers

Answer 1

Answer:

Reactions occur when two or more molecules interact and the molecules change. ... Bonds between atoms are broken and created to form new molecules. That's it.

Explanation:


Related Questions

The pictures below show samples of different substances.
The mass and volume of each sample differ from the mass and volume of the other samples. Is it possible for each sample to contain 1 mol of each substance?

A. No, because they have different masses.
B. No, because they have different volumes.
C. Yes, if each sample contains 6.02 x 10^23 atoms.
D. Yes, if each sample contains 2 amu.

Answers

Answer:

C. Yes, if each sample contains 6.02 x 10²³ atoms.

Explanation:

It is possible for each sample to contain 1 mole of each sample if and only if each of the sample if made up of 6.02 x 10²³ atoms.

6.02 x 10²³ atoms is the Avogadro's number. This number is equivalent to a mole of a substance.

If the amount of matter in the given substance is at least one mole, it is possible that they are made up of one mole each of each substance. If they contain lesser amount of atoms, then it is not up to one mole of substance. But if it is greater, then, we can have even more than one mole of substance.

A mole is simply a unit of measurement and it is equivalent to 6.02 x 10²³ atoms.

Answer:

C

Explanation:

i just took the test

:)

what is the theoretical yield (in mols) of magnesium when 1.1 x 102 mols of lithium reacts with excess magnesium chloride.

Answers

Explanation:

Use the molecular formula to find the molar mass; to obtain the number of moles, divide the mass of compound by the molar mass of the compound expressed in grams.

hello, please can you solve my question:
an atom contains 22 protons and 26 neutrons. What is it's mass number?

I will mark brainliest

Answers

Mass number is sum of protons and neutrons so 22+26
The sum would be 48
Mass number is 48

9 of 16
9.
A student drops a ball from 5 feet above the ground. After bouncing once, it only reaches
a maximum height of 4 feet above the ground.
Use energy terms to explain why the ball did not reach its original height after bouncing
once.
A. Some energy was lost
B. Some energy was transferred to the floor and air
C. Some energy disappeared when it hit the floor
D. Some energy was destroyed

Answers

A. Some energy was lost.

The energy would have been lost to the atmosphere as sound energy or heat energy as the ball hit the floor.

Do you think that it is necessary and/or important to take a multivitamin everyday to maintain optimal health? What might help you answer this question? What types of things might influence your decision to take a multivitamin every day?
What's ur opinion with explanation???????!!!!!!!!!!

Answers

I do not think it is necessary to take a multivitamin everyday. To maintain optimal health, people should eat a balanced diet with low processed food and stay active. Looking into your daily health habits can help determine if you want to take multivitamins. Factors such as level of activity, diet, time outside, and physical condition can influence this decision.

To have a system you need more than one magnet .
true or false


Answers

Answer:

True

Explanation:

Answer: true

Explanation:

Atoms of which two elements have a combined total of 23 protons?
A.Sodium, Na, and magnesium, Mg
B.Boron, B, and carbon, C
C.Copper, Cu, and zinc, Zn
D.None of these

Answers

Answer:

A

Explanation:

Sodium has 11 electrons and Magnesium has 12 electrons. Since here you need to consider atoms, they must have equal amount of protons as electrons to be considered neutral, and so an atom.

So simply 11+12 =23

Explain the effect of pressure on the following chemical equation :
[tex]CaCO_3 = CaO + CO_2[/tex]
2. Explain the effect of concentration in the following equation :
[tex]3Fe \: +4H_2O= Fe_3 \: O_4 + 4H_2[/tex]

Answers

Answer:

Explanation:

One

Pressure will favor the side with the least number of mols if it the larger number of moles counts only the gases. (Le Chetalier's Principle). In this case both CaCO3 and CaO are not soluble in water. The only gas is CO2. Since it represents the most number of mols the reactant is favored.

More or Less are very troublesome words in beginning science. Make sure you understand their meaning for this question. The more pressure applied, the more the reactants will be favored and the equation shifts left.

Two

Fe and Fe3O4 are both solids. It depends on the form that water takes. Looking it up, it is shown to be in a gas form. That means if you increase the pressure, nothing will happen. That is not your question, but you should note it.

The answer to your question is you increase the concentration of Fe or H2O, the equilibrium will shift right.

If you add more Fe3O4 or hydrogen it will shift left.

Chemists say that if you alter the equilibrium the equation will shift in the opposite direction to compensate for the action you have taken.

Can someone help me answer this ASAP !!!

Answers

Answer: Chlorine I think

Explanation:

Chlorine is added to the water to kill germs. When it is added to a swimming pool, it forms a weak acid called hypochlorous acid that kills bacteria like salmonella and E.

Answer: Chlorine!

Explanation:

When it is added to a swimming pool, it forms a weak acid called hypochlorous acid that kills bacteria like salmonella and E. coli, as well as germs that cause viruses such as diarrhea and swimmer's ear.

How much heat is necessary to change 10.0g of water from 20 degrees celsius to 75 degrees celsius

Answers

Answer:

6

Explanation:

1. Electronegativities of the elements Be, Mg, Ca, and Sr follow a specific trend within their group. Based on this trend, the atoms of which element will have the least attraction for an electron?
A) Be.
B) Mg.
C) Ca.
D) Sr.

2. Which element has a larger atomic radius than sulfur?
A) Chlorine.
B) Cadmium.
C) Fluorine.
D) Oxygen.

3. Which ion was formed by providing the second ionization energy to remove an electron?
A) Ca2+.
B) N3–.
C) Fe3+.
D) S2–.

4. The most negative electron affinity is most likely associated with which type of atoms?
A) Large nonmetal atoms.
B) Small nonmetal atoms.
C) Large metal atoms.
D) Small metal atoms.

5. Selected properties of antimony (Sb) and iodine (I) are listed in the table below.

Element AtomRadius(pm) 1st IonEnergy(kJ/mol) ElectroAffinity(kJ/mol) Electronegative
Sb 145 ? –103 2.05
I 140 1008 –295 ?

Which predictions can most likely be made?
Sb has a lower ionization energy but a higher electronegativity than I.
Sb has a higher ionization energy but a lower electronegativity than I.
Sb has a lower ionization energy and a lower electronegativity than I.
Sb has a higher ionization energy and a higher electronegativity than I.

6. Which correctly summarizes the trend in electron affinity?
A) It tends to be very high for group 2.
B) It tends to be more negative across a period.
C) It tends to remain the same across periods.
D) It tends to be more negative down a group.

7. Which explains the change in ionization energy that occurs between removing the first and second electrons from an atom?
A) The ionization energy decreases because the ratio of the protons to electrons increases.
B) The ionization energy increases because the ratio of the protons to electrons increases.
C) The ionization energy decreases because the ratio of the protons to electrons decreases.
D) The ionization energy increases because the ratio of the protons to electrons decreases.

8. Which element would most likely have an electron affinity measuring closest to zero?
A) Na.
B) Al.
C) Rb.
D) Ar.

9. Electronegativities of the elements Na, Al, P, and Cl follow a specific trend across the period. Based on this trend, an electron will be most strongly attracted to
A) Na.
B) Al.
C) P.
D) Cl.

10. Which best describes ionization energy?
A) Energy needed to add an electron to a neutral atom in the gas phase.
B) Energy needed to add an electron to a neutral atom in the liquid phase.
C) Energy needed to remove an electron from an atom or ion in the gas phase.
D) Energy needed to remove an electron from an atom or ion in the liquid phase.

Answers

Answer: B D B A C B E D A B

Explanation:

A chemical reaction yields 1 mole of lithium hydroxide (LiOH). How many grams of
lithium hydroxide are present?
3 g
48 g
728
24 g

Answers

Mass of LiOH= 23.95 grams ≈ 24 g

Further explanation

Given

1 mole of lithium hydroxide (LiOH)

Required

Mass of LiOH

Solution

The mole is the number of particles contained in a substance

1 mol = 6.02.10²³

Moles can also be determined from the amount of substance mass and its molar mass

n = mass : molar mass

Input the value :

mass = n x molar mass

mass = 1 mole x 23,95 g/mol

mass = 23.95 grams ≈ 24 g

 

The mass of 1 mole LiOH has been 24 g. Thus, option D is correct.

The mass of a compound present in a mole of sample has been equivalent to the molar mass of the compound. The molar mass of the compound has been the sum of the constituent in a formula unit.

The molar mass of lithium hydroxide (mwt) has been given as:

[tex]mwt=m_L_i\;+\;m_O\;+\;m_H[/tex]

Where, the mass of Li is [tex]m_L_i=6.941\;\rm g[/tex]

The mass of oxygen is [tex]m_O=16\;\rm g[/tex]

The mass of hydrogen is [tex]m_H=1\;\rm g[/tex]

Substituting the values for molar mass (mwt) of LiOH:

[tex]mwt=6.941\;+\;16\;+\;1\;\text g\\mwt=23.941\;\text g\\mwt=24\;\text g[/tex]

The molar mass of LiOH has been 24 g.

The molar mass has been equivalent to the mass of 1 mole of sample. Thus, the mass of 1 mole LiOH has been 24 g. Thus, option D is correct.

For more information about mass of mole, refer to the link:

https://brainly.com/question/1370888

How could we separate the baking soda from the after after it had already been mixed in? helppp!!!

Answers

Answer:

i thing by filtering

Explanation:

Place the following metals in order of most reactive to least:
Aluminium
Calcium
Copper
Iron
Magnesium
Sodium
Zinc

Answers

Answer:

Sodium

Calcium

Magnesium

Aluminium

Zinc

Iron

Copper

Explanation:

For 30 points pls help me with this question

Answers

Answer:

a put a as you answer you rock do not give up on your dreams

An atom has 9 protons and 7 electrons. What is its overall charge?

Answers

Answer:

Positive

Explanation:

If an atom has more protons than electrons, its overall charge will be positive. Protons have a positive charge, electrons have a negative charge.

1. If a cell has waste it needs to store, it will store it:​

Answers

it will store it in the vacuole :)

If the theoretical yield of a reaction was calculated to be 42.6 grams and when the
experiment was conducted the amount produced was 20.7 grams, the what is the percent
yield of the experiment?

Answers

Answer:

48.59%

Explanation:

theoretical yield = 42.6g

actual yield = 20.7g

% yield = 20.7/42.6 x 100 = 48.59% (2 d.p.)

Please help me out with this assignment

Answers

Answer:

1. 7 meters

2. gullet

4. Not sure about this

6. strong

7. digestive

8. starch

12. Not sure about this either

14. Water

15. Jejunum

19. teeth

Hope this helps!

If the density is 0.9g/cm3 and the volume is 1.5cm3 ? What is the Mass?

Answers

Answer:

1.35g

Explanation:

times the density and volume together to get the mass

0.9 x 1.5 = 1.35g

Which of the following materials has the highest density?
A. O water vapor
B. O steam
C. O liquid water
D. O ice

Answers

Answer:

Answer is C. liquid water.

Explanation:

I hope it's helpful!

Liquid water has the highest density. Therefore, the correct option is option C among all the given options.

What is density?

The density of a substance is defined just like its weight per unit volume. In other words, density is the mass-to-volume ratio or mass for every unit volume. It quantifies how much "stuff" a thing possesses in an unit volume (cubic meter or cubic centimeter).

Density is a measure of how closely stuff is packed together. The density principle was established by the Greek scholar Archimedes, which is simple to compute if one know the equation and its associated units.  Lquid water has the highest density.

Therefore, the correct option is option C among all the given options.

To learn more about density, here:

https://brainly.com/question/29775886

#SPJ6


PLEASE HELP I WILL MARK AS BRAINLESS 12+ POINTS!!

Which of the following reasons BEST explains why thunderstorms are likely to form on a hot day?

A warm, humid air rises quickly and then condenses into rain clouds.

B) as air rises, it loses temperature and causes rain.

C the air is usually calm and allows the clouds to form

D the air drops quickly and forms low level cloud layers.

Answers

Answer:

A

Explanation:

The high humidity, in conjunction with warm temperatures, creates massive amounts of warm, moist air rising into the atmosphere, where it can easily form a thunderstorm. As the process of evaporation and condensation occurs, these droplets collide with other moisture that is condensing as it rises.


I will give you a lot of points help me ASAP please I am begging you

Answers

Answer:

hope this helps

Explanation:

i need help please this is due today

Answers

Option B is correct. Average speed can be found through the equation speed = distance/time. Applying this to each person using the data in the chart:

Dennis’ speed: 60 ft/0.5 secs = 120 ft per sec

Johnny’s speed: 60 ft/0.45 secs = 133.333 ft per sec

Travis’ speed: 60 ft/0.52 secs = 115.38 ft per sec

Michael’s speed: 60 ft/0.48 secs = 125 ft per sec

As you can see, Johnny’s speed is the fastest at 133.333 ft/sec.

If the mass of an object is 15kg and the volume of an object is 15ml, what is its density?
0 225kg/ml
Okg/ml
1kg/ml
30kg/ml

Answers

Answer:

1kg/ml

Explanation:

please help me i really am struggling

Answers

Answer:

It is visible light

Explanation:

it’s the visible light

Car 1 has a body made from aluminium and car 2 has a body made from steel. Which car is likely to
have the better fuel economy?​

Answers

Answer:

1

Explanation:

Um well if a car is made out aluminum keep in mind the engine = heat and stuff the type of stuff that would burn would cause chemicals/ white flame to form the trioxide aluminum(lll) oxide, Al small 2 O small 3. With Steel this would burn off bits of rust/ion oxide

I could be wrong but thats the best answer i can give sorry mate

PLs help mweee Ill mark brainliest

Answers

Answer:

I'm pretty sure that it's plate movement...

i am not sure i am thinking A and C

Answers

Answer:

I think so too

Explanation:

9

A 75 gram sample of water is initially at 30 degrees Celsius. What would it's temperature be if
it absorbed 2000 J of heat?

Answers

Answer:

T2 = 36.38°C

Explanation:

Given data:

Mass of water = 75 g

Initial temperature = 30 °C

Final temperature = ?

Heat absorbed = 2000 J

Solution:

Specific heat capacity of water is 4.18 J/g.°C

Formula:

Q = m.c. ΔT

Q = amount of heat absorbed or released

m = mass of given substance

c = specific heat capacity of substance

ΔT = change in temperature

ΔT = Final temperature - initial temperature

2000 J = 75 g×4.18 J/g.°C × T2- T1

2000 J = 313.5 J/°C × T2- T1

2000 J = 313.5 J/°C × T2 - 30 °C

2000 J / 313.5 J/°C  = T2 - 30 °C

6.38 °C = T2 - 30 °C

T2 = 6.38 °C +  30°C

T2 = 36.38°C

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