If a chemical reaction occurs in a flask, and the flask becomes colder, the reaction was exothermic. true or false

Answers

Answer 1

Answer:

false

Explanation:

hope this helps you

Answer 2

Answer:

False, if the flask becomes colder it's endothermic. I hope this helps! :)


Related Questions

Which are proteins that recognize specific proteins on bacteria a.antibodies b.enzymes c.nutrients d.receptors

Answers

Answer:

A

Explanation:

Answer:

A. antibodies

Explanation:

how many electrons can occupy the 4p sublevel of a neutral atom of bromine

Answers

Answer:

6

Explanation

every p sublevel holds up to 6 electrons

so the 4p sublevel  must hold up to 6 electonsr

help plssssssssssssssss??

Answers

Answer:

Chemical properties, such as combustibility, are generally observed as the identity of a substance changes and one or more new substances form.

Explanation:

Chemical change involves formation of new substances. Therefore, the correct answer is "Chemical properties, such as combustibility, are generally observed as the identity of a substance changes and one or more new substances form."

Balance the following equation:
C7H602 + 02 -- CO2 + H20

Answers

Answer:

Explanation:

2C7H6O2 + 15O2 → 14CO2 + 6H2O.

Read that From picture and tell me the answer please​

Answers

Answer:

1g Hydrogen

Explanation:

Getting to the equation:

Calcium in water reacts vigorously to give a cloudy white Precipitate (compound) called Calcium hydroxide alongwith the evolution of Hydrogen gas.

[tex] \boxed{ \mathsf{Ca + H_2O \rightarrow Ca(OH)_2 + H_2}}[/tex]

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Balancing the equation:

This reaction is not in it's balanced form! The number of atoms of Hydrogen on the left is 2 while that on the right is 4,I.e.,they're not equal.

Adding a 2 in front of H2O solves the problem by making the number of atoms of each element on both the sides equal.

[tex] \mathsf{Ca +2 H_2O \rightarrow Ca(OH)_2 + H_2}[/tex]

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Observations:

Looking into the equation more carefully, we see:

1 atom of Calcium reacts with 2 molecules of water to give 1 molecule of Calcium Hydroxide alongwith 1 molecule of Hydrogen gas.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Gram atomic and molecular masses

Mass of one atom of Calcium = it's gram atomic mass

= 40 g

Mass of one "molecule" of Hydrogen

= it's Gram molecular mass

= gram mass of one atom × number of atoms in one molecule

= 1 × 2

= 2 g

So,

according to our observation:

One atoms of Calcium gives one molecule of Hydrogen (during the particular reaction)

=> 40g of Calcium gives = 2g of Hydrogen

•°• 1 g of Calcium gives = [tex] \frac{2}{40} [/tex]

= [tex] \frac{1}{20} [/tex] g Hydrogen

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Answer:

We're provided with 20g of Calcium,

=> 20g of Calcium gives = 20 × [tex] \frac{1}{20} [/tex] g H2

= 1 g H2

_______________

Hope this helps!

Someone pls help me I will make you brain

Answers

Your best answer would be C. Im not completely sure but i hope this will help!

ANSWER : I AND III

HOPE IT HELPED

HELPPPP PLEASE WILLLL GIVE BRIANLIESTTTT

Answers

Answer: 105 mL

Explanation:

We can use the formula M₁V₁ = M₂V₂ the total volume of water that will yield 0.800 M HCl. We can then subtract that from the initial volume to get how much water needs to be added.

Since M₁V₁ = M₂V₂    (starting mole× starting volume = end mole × end volume)

⇒  (5 mol)(20 mL) = (0.80 mol) V₂

         100 mol/mL = 0.8 mol × V₂

⇒                      V₂ = 100 mol/mL ÷ 0.8 mol

                             = 125 m

Since we began with 20.0 mL of water,

water needed to add = 125 mL - 20 mL = 105 mL

                                   

what is the source of the carbon plants use to make organic molecules?

Answers

Answer:

Carbon dioxide serves as the source of carbon,

Explanation:

The atomic number equals blank of blank electrons

Answers

Answer:

The atomic number equals number of protons and electrons

This is true when an atom is in neutral state.

how do ions form bonds, and describe the structure of the resulting compound.​

Answers

Answer:

Electrons are transferred between atoms together in the ionic compound. The ions are arranged in a regular repeating pattern in an ionic crystal

Explanation:

Ions electrostatically attracts its counter ions and forms the ionic bond between these ions. The structure of ionic compounds depends on the number of atoms and bonded pair of electrons.

What is ionic bonding ?

Ionic bonds are formed between metals and non-metals. Metals are electron rich and easily loss one or more electrons to the electron deficient non metals.

The loss of electrons make the atom forms a positive ion called cations. The gain of electrons make the formation of anions or negative ions. These positive ions and negative ions attracts electrostatically and forms ionic bond between them.

The structure of ionic compounds depends on the number of bonded atoms, size, presence of lone pairs etc. In solution ionic compounds exists as separate ions.

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If you were able to magnify a penny down to the atomic level, what two
observations could you make about the atoms?

Answers

The two observations you would make about the atoms are

They are made up largely of empty spaceTheir mass is concentrated at the center called a nucleus

These observations were made by Ernest Rutherford in his model of the atom established in 1911, when he performed his gold foil experiment and observed the scattering angle of the alpha particles which led him to conclude that the mass of the atom was concentrated at the center.

Also, that most of the alpha particles also went through the gold foil suggested that the atom was made up basically of empty space.

So,

The two observations you would make about the atoms are

They are made up largely of empty spaceTheir mass is concentrated at the center called a nucleus

Learn more about the atom here:

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13. An atom has 8 protons, 8 electrons, and 7 neutrons. What is the charge of the
atom and what type of ion is it?

Answers

Answer:

oxygen

Explanation:

14. A gas in a 400 ml flask exerts pressure of 81.0 kPa at 25.0°C. If the gas
was in a 250 ml container at a pressure of 101 kPa, the temperature would be
a) - 124 °C
b) - 41.2°C
c) 20.0°C
d) 232 °C

Answers

Answer: B would be the correct answer

Explanation: You will need to use P1V1/T1=P2V2/T2

So

P1= 81.0kPa /101 =0.799atm

V1=0.4L

T1=25.0C +273.15K= 298.15K

P2= 101kPa /101 = 1atm

V2=0.25L

T2= ?

T2=P2V2T1/P1V1

(1.0atm)(0.25L)(298.15K)/(0.799atm)(0.4L) =233.22K-273.15=-39.92C

a standard solution is made by diluting a small volume of stock solution. if 2.42 ml of stock solution is mixed with 7.55 ml of water, what is the concentration of the diluted solution? the stock solution concentration is 0.197 m.

Answers

Taking into account the definition of dilution, the concentration of the diluted solution is 0.063 M.

Dilution

When it is desired to prepare a less concentrated solution from a more concentrated one, it is called dilution.

Dilution is the process of reducing the concentration of solute in solution, which is accomplished by simply adding more solvent to the solution at the same amount of solute.

In a dilution the amount of solute does not change, but as more solvent is added, the concentration of the solute decreases, as the volume (and weight) of the solution increases.

A dilution is mathematically expressed as:

Ci×Vi = Cf×Vf

where

Ci: initial concentrationVi: initial volumeCf: final concentrationVf: final volume

Concentration of the diluted solution

In this case, you know:

Ci= 0.197 MVi= 2.42 mLCf= ?Vf= 7.55 mL

Replacing in the definition of dilution:

0.197 M× 2.42 mL= Cf× 7.55 mL

Solving:

(0.197 M× 2.42 mL)÷ 7.55 mL= Cf

0.063 M= Cf

In summary, the concentration of the diluted solution is 0.063 M.

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Chemical and physical properties of the seaborgium element

Answers

Answer:

Seaborgium is an artificially produced radioactive chemical element, it's appearance is unknown, it probably has a silvery white or metallic gray colour. The most stable isotope Sg 271 has an half life of 2.4 minutes.

pls hurry
Which important law states that when elements are arranged by atomic number, similarities in chemical properties exist?
1)Periodic Law
2)Mendeleev's 1st law
3)Law of Atomic Structure
4)Theory of Periodic Succession

Answers

Answer:

plusses give me brainliest after this

The answer is: 1. periodic table

Is it _________
To view _______ eclipse without eve protection.
A.Unsafe, lunar
B.Safe, solar
C.Unsafe, solar
D.Unsafe new moon

Answers

Answer:

unsafe, solar

Explanation:

A lunar eclipse covers the moon which is safe to look at. New Moon, again is simply the moon. However, we should never look at the sun, eclipsed or not!

Answer:

C, it is unsafe to view solar

without eye protection

who is considered the father of the periodic table

Answers

Answer:

Dmitri Mendeleev

Explanation:

A field of many different species of wildflowers would be considered a(n) _____________.

a
organism
b
population
c
community
d
ecosystem
e
biome
f
biosphere

Answers

Answer:

That would be a community.

Explanation:

A field of many different species of wildflowers is considered to be a community.

What is community in biological terms?

It is called biological community meaning an interacting  group of various species sharing a common location.Factors which determine overall structure of community  are number of species, abundance of each species,interaction among the species and community's ability to return to normal after a natural calamity.

Change of communities over a period of  time is called as ecological succession.Each species in a community has its own characteristic niche . The niche includes all the interactions of the species with other members of the community.An ecosystem comprises of biological community together with its physical environment.

Learn more about biological community,here:

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During chemical reactions__________are broken and___________to form
new substances with different properties, but mass is still_____________ .

Answers

Answer:

1st blank : Atoms

2nd blank : Reactants

I'm still trying to find the 3rd blank. I'll put it in comments if I find it

Explanation:

Hope this helps :)

Pls make brainliest :}

And have an amazing day <3

How would the electron configuration of nitrogen change to make a stable configuration?
It would lose four electrons.
It would gain three electrons.
It would gain two electrons.
It would lose five electrons.

Which quantity determines how two atoms bond?
the difference in the number of valence electrons
the difference in their electronegativities
their total number of valence electrons
the sum of their electronegativities

Which statement best explains why the elements in Group 18 do not have electronegativity values?
The elements do not have electrons.
The elements are too large.
The elements have filled valence levels.
The elements have only one electron shell.

Based on patterns in the periodic table, which ion has a stable valence electron configuration?
potassium (K) with a 1+ charge
magnesium (Mg) with a 1− charge
sulfur (S) with a 1− charge
fluorine (F) with a 1+ charge

Which chemical formula represents a polyatomic ion?(1 point)
Na+
Cl–
NaCl
ClO–

Answers

The answers to the questions are as follows;

It would gain three electronsThe difference in their electronegativities.The elements have filled Valence levelspotassium (K) with a 1+ chargeClO-

Question 1:

How would the electron configuration of nitrogen change to make a stable configuration?

Since Nitrogen has 5 Valence electrons, it needs 3 electrons to attain it's octet configuration. As such, it gains 3 electrons.

Question 2:

Which quantity determines how two atoms bond.

The quantity which determines how two atoms bond is The difference in their electronegativities.

Question 3:

Which statement best explains why the elements in Group 18 do not have electronegativity values.

This is because the elements have filled Valence levels.

Question 4:

Based on patterns in the periodic table, which ion has a stable valence electron configuration

The ion which has a stable Valence electron configuration is potassium (K) with a 1+ charge

Question 5;

Which chemical formula represents a polyatomic ion?

The chemical formula which represents a polyatomic ion is; ClO-

is a paper clip homogeneous or heterogenous? substance or mixture? solution, colloid, suspension?

Answers

Explanation: It is an alloy, very probable, not homogeneous.

                  A metal paper clip is usually steel, an alloy of iron, carbon, and other elements in various amounts.  A plastic paper clip is composed of a polymer, a very complex compound.

                   A paper clip is a Colloid

i guess this helped you pls mark me as brainliest

Question 116 g of sunflower oil is
used in a recipe. The density of the
oil is 0.925 g/mL. What is the volume
of the sunflower oil in mL?

Answers

Answer:  125.41 mL

Explanation:

Volume = mass ÷ density

             =  116 g  ÷  0.925 g/mL

             =  125.41 mL

A 116 g of sunflower oil of 0.925 g/mL has a volume of 125.41 mL.

Please help I am stuck on this question

Answers

i think the answer is nervus cell because they work togtter to form the brain

What is the Golgi body made of?
O integral proteins
O large steroids
O RNA
O the same thing as the cell membrane

Answers

Explanation:

integral proteins...nns

a change in the composition of matter _____________ occurs during a chemical reaction.

Answers

Answer: During a chemical change, the composition of matter always changes

Explanation:

Ionization energy and electronegativity show similar trends in the periodic table. Describe these trends. What is the significance of the similarity of these trends?

Answers

Electronegativity measures how much an atom likes to pull electrons away from another one. Ionization energy measures how much an atom doesn't want to lose electrons. As an atom that wants to gain electrons will clearly not want to lose electrons, these trends are basically identical.

Taking into account the definition of ionization energy and electronegativity, you can say that the significance of the similarity of these trends  is that while electrons are more attracted to the nucleus (electronegativity), more energy is needed to extract an electron from a neutral atom (ionization energy).

Ionization energy

Electrons are held in atoms by their attraction to the nucleus, which means that energy is needed to remove an electron from the atom.

Ionization energy, also called ionization potential, is the necessary energy that must be supplied to a neutral, gaseous, ground-state atom to remove an electron from an atom. When an electron is removed from a neutral atom, a cation with a charge equal to +1 is formed.

The further away the electron is from the nucleus, the easier it is to remove it, that is, the less energy is needed.

In a group the atoms have the same electronic structure in the outermost shell. But when going down in the same group, the electrons find themselves in shells that are farther and farther away from the nucleus, being less and less attracted. The size of the atom increases as the number of electronic shells increases, increasing the atomic radius when descending in a group. But the electrons are farther from the nucleus, and the easier it will be to expel them. That is, its extraction from the atom is facilitated. So the ionization energy decreases when descending in a group. In other words, ionization energy is a function of atomic radius; the larger the radius, the less energy is required to remove the electron from the outermost orbital.

By increasing the atomic number of the elements of the same period, the nuclear attraction on the outermost electron increases, since the atomic radius decreases and the effective nuclear charge on it increases.

For this reason, in a period, as the atomic number increases, the ionization energy becomes greater.

Electronegativity

The electronegativity of an element is defined as the relative ability of an atom to attract electrons from another atom to chemically bond and form a compound.

In other words, electronegativity is a measure of the attractive force that one atom exerts on the electrons of another when a chemical bond forms.

In the groups, the electronegativity decreases from top to bottom because the valence shell moves away from the nucleus and with this the attraction that the nucleus exerts on the valence electrons decreases.

In the periods, the electronegativity increases from left to right, because the number of electrons in the valence shell increases, so the attraction of other electrons increases to complete the valence shell and reach a stable state.

Similarityof the trends

The significance of the similarity of these trends  is that while electrons are more attracted to the nucleus (electronegativity), more energy is needed to extract an electron from a neutral atom (ionization energy).

Then, electronegativity is related to ionization energy in the following way: an atom with a high ionization potential has a high electronegativity. On the contrary, atoms with low ionization potential have small electronegativity.

Learn more about

electronegativity: brainly.com/question/14481608?referrer=searchResults brainly.com/question/21298480?referrer=searchResultsionization energy:brainly.com/question/16243729?referrer=searchResults brainly.com/question/11623163?referrer=searchResults brainly.com/question/1602374?referrer=searchResults

Migration can best enhance the survival of individuals because it

Answers

Answer:

It can enhance survival because the animals for example birds are migrating to those places for high or increasing resources

Explanation:

Which statement accurately describes the bond that forms between carbon and oxygen to create carbon dioxide

Answers

Answer:

the bond that forms between carbon and oxygen to create carbon dioxide

A polar covalent bond

An atom is electrically neutral when...
O The number of protons and neutrons are equal.
O The number of protons and electrons are equal.
O The number of neutrons and electrons are equal.
O The neutrons balance the protons and electrons.

Answers

Answer:

The number of protons and electrons are equal.

Explanation:

When an atom has an equal number of electrons and protons, it has an equal number of negative electric charges (the electrons) and positive electric charges (the protons). The total electric charge of the atom is therefore zero and the atom is said to be neutral.

Other Questions
In terms of attractive forces, explain why LiClhas a higher melting point than SCI2. They have decided to clean up the neighbourhood ________ it is full of rubbish.A. so B. but C. although D. because A market sells chicken for $2.99 a pound Do you think you would have judged Debbie the same way the members of the golf team did before getting to know her? Explain why or why not. * how are risk factors and cumulative factors compared Mrs. Blake needs to hire a babysitter. Kelsey charges $6 per hour plus a $5 fee. Lauren charges $4 per hour, plus a $10 fee. Mrs. Blake set up this equation to figure out for what amount of time both babysitters charge the same.6h + 5 = 4h + 10What is the correct sequence of steps to solve Mrs. Blakes equation? A. Subtract 6h from both sides. Subtract 5 from both sides. Divide each side by 2. B. Subtract 4h from both sides. Subtract 5 from both sides. Divide each side by 2. C. Subtract 4h from both sides. Add 5 to both sides. Divide each side by 2. D. Subtract 4h from both sides. Subtract 5 from both sides. Divide each side by 6. What did you like about this Unit?*Your answerI What is the density of a gas with a volume of 5.6 FL oz. and a mass of 37 grams? Definition: To solve a problem, we often______the given information into algebraic expressions andExample: The phrase "4 more than twice a number' becomes 2n + 4'. If you cut a 3 3/4 ft. length of wire into pieces that 1/4 ft. long, how many pieces of wire will you have? A circular flowerbed is surrounded by a path 2.5m wide .The diameter of the flower bed is 40m. Find the area of the path . 2. How were scientists able to access a car's computer system?3. What other looming dangers are there for drivers of newer, computer controlled responsible for the fact that organic molecules no longer spontaneously form on Earth? Writing an Informative Essay about the Immigrant Experience with sources 1.We went to yoga class I felt better. -6 divided by 8? How do you turn it into a fraction problem? Find x and y intercept 5x + 4y = 8 3. Ecosystems haveedge. Question 1 of 10Which of the following sentences is most clearly describing a theme?A Imagination is more important than intellect.B. Dark Shadows lay across the path like the bars of a cage.o0The golden feather represents Mrs. Whitherby's soul.D The Second World War lasted from 1939 to 1945.SUBMIt Personal letters, even ones such as Wheatley's that were later published innewspapers, offer a rare opportunity to hear women's voices from the past. Whatdistinguishes Wheatley's and Adams's writing from the rhetoric of Patrick Henry,Thomas Jefferson, and Tom Paine? What do their letters reveal about how womenwere expected to behave in early America?