Which statement about exothermic reactions is TRUE?
A.In an exothermic reaction, energy is absorbed, bonds are broken, and the temperature decreases.
B. In an exothermic reaction, energy is released, bonds are formed, and the temperature increases.A sample of an unknown solid is found to have a volume of 24.3 cm3 and a mass of
217.0 grams. What is the density of the unknown
Density = mass ÷ volume
= 217.0 g ÷ 24.3 cm³
= 8.93 g/cm³
∴ the unknown sample of mass 217.0 grams and volume of 24.3 cm³ has a density of 8.93 g/cm³.is it true or false when the there are too many protons making the nuclei unstable, it will undergo a positron decay and a proton will turn into a neutron.
Answer:
True
Explanation:
As the number of protons in the nucleus increases, the number of neutrons needed for a stable nucleus increases even more rapidly.
Which of the following are products of combustion?
liquid and solid water
newly discovered elements
additional atoms
heat and light
The answer option which are products of combustion is: D. Heat and light.
In Chemistry, there are five (5) main types of chemical reaction and these include;
Combination reaction.Double-replacement reaction.Decomposition reaction.Single-replacement reaction.Combustion reaction.A combustion reaction can be defined as an exothermic chemical reaction between physical substances, usually in the presence of oxygen and hydrocarbons to produce heat, light and carbon.
An example of a combustion reaction is the burning of forest trees and plants.
In conclusion, the products of combustion are heat and light.
Read more: https://brainly.com/question/21453409
Answer:
heat and light
Explanation:
Số amin bậc một có cùng công thức phân tử C3H9N là
A. 3. B. 1. C. 2. D. 4
Answer:
A.3
Three primary amines
Ba amin chính
Two different medical students made models to show their ideas about the molecules that should be in the functioning cells of a healthy body. Using what you have figured out from reading and investigating so far, evaluate the models by answering the questions following the models.
Are these models accurate? choose one)
Medical Student A’s model is accurate.
Medical Student B’s model is accurate.
Both models are accurate.
Neither model is accurate.
Answer:
A
Explanation:
it's a because model is like the same thing as walking on a Runway but it's like a model in the medical field
convert 1 bromopropane to bromoethane.
Answer:
The Dehydrohaogenation of 1-bromo propane with alcoholic KOH gives propene which on again hydrohalogenation with HBr gives 2-bromo propane due to Markonikove's rule for addition.
Explanation:
What is the temperature of Spica?
Answer:
Mark me brianliest plzzzzzzzzzzzz (puppy eyes) plz
Explanation:
22,400 Kelvin
22,400 KelvinSpica A and B are both classified as B-type stars and are very hot, with surface temperatures of 22,400 Kelvin and 18,500 Kelvin respectively. The primary component has a luminosity of some 12,100 Suns while the secondary shines with the power of 1500 Suns.
in order for a circuit work there can be no _______ within the circuit?
which elements are designated as the alkali metals
Answer:
Lithium (Li), Sodium (Na), Potassium (K), Rubidium (Rb), Cesium (Cs), and Francium (Fr).
Explanation:
Six chemical elements in Group 1, the leftmost column in the periodic table.
Hope this helps!
wants to help?
it's agriculture science not chemistry
Answer:
the jamaians need food to survive
Explanation:
Unless otherwise instructed, you may refer to the periodic table in the Chemistry: Problems and Solutions book for this question.
Which element belongs to the p-block?
cobalt
oxygen
rubidium
hydrogen
Someone pls help me I will make you brain
Answer:
Lung function decreses at a faster rate for young people (last answer choice)
Explanation:
write the 5 major characteristics of traditional map making
Answer:
insta
Explanation:
Zak_1231 follow me
What would cause a liquid to turn into a solid?
Answer:
Freezing the liquid
Explanation:
Freezing a liquid causes a liquid to become a soild.
Answer:
changing the temperature of the liquid
Explanation:
Ex. Cooking brownie batter(liquid), turns it into an edible brownie(solid). Ex. Putting water into a freezer freezes it, turning it into a solid.
hi everyone can anyone help with this, the question and diagram is in the pic thx!
Answer:
QP
Explanation:
P has 9 electrons.
Electronic Configuration : 2, 7
Valence electrons : 7
P needs 1 electron to get stable electronic configuration.
Q has 3 electrons.
Electronic Configuration : 2, 1
Valence electrons : 1
P needs to loose 1 electron to get stable electronic configuration.
Q donates 1 electron,
Q -----> Q+ + 1 e-
P gains 1 electron,
P + 1 e- -----> P-
Q+ + P- -----> QP
This is an ionic compound.
how to make slime without borax or contact solution
Answer:
lysol and glue pretty simple.
Explanation:
Answer:
glue, and some laundry detergent.
Explanation:
only some laundry detergents work.
for a butter slime all you need is Elmer's wood glue, and gel shaving foam it makes a thick butter like consistency slime.
if you want to get fancy you can add a drop of food coloring and sparkles. these work good for me, you should give them a try. thank you and have a great day! if you like my answer please mark brailyist thanks again. if you have any questions please feel free to ask me! thanks again.
Compare and contrast how light acts as a wave and as a particle
here you go
Explanation:
the flow of photons is a wave. ... The various properties of light, which is a type of electromagnetic wave, are due to the behavior of extremely small particles called photons that are invisible to the naked eye
the reaction of zinc metal and hydrochloric acid produces hydrogen gas and zinc chloride. true or false?
Answer:
true.
Explanation:
Zn(s) + 2HCI(aq)=H2(g)+ZnCl2(g)
what if water didnt have a negative charge?
Answer:
Explanation:
It would be positively charge
The period of the vibrating string is 0.004 seconds. What is the frequency of the
standing wave?
Answer:4
Explanation:
The specific heat of wood is 2.03 J/g.°C. How much
heat is needed to convert 225 g of wood at -15.0°C to
10.0°C?
Answer:
11419 J/g/ 11.419 KJ/g
Explanation:
H=MCQ
H=225×2.03×(-15-10)
H=225×2.03(25) Note; negative sign is of no use
H=11419J/g
6. Which of the following is a binary compound?
a. CaCO3
b. CuSO4
c. H2O
d. Pb(NO3)2
Answer:
The answer to your question is c. H2O
Explanation:
a. CaCO3 ----> Calcium Carbonate is obviously not a binary compound because it contains more than two elements.
b. CuSO4 ----> CuSO4 stands for copper(II) sulfate. Sulfate is the polyatomic ion SO4 -2.
c. H2O ----> Binary molecular compounds are composed of only two elements. Examples are H2O, NO, SF6 etc.
d. Pb(NO3)2 ----> Lead(II) nitrate is an inorganic compound with the chemical formula Pb(NO3)2.
I hope this helps and have a great day!
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.
Taking into account the definition of dilution, the concentration of the diluted solution is 0.063 M.
DilutionWhen 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 volumeConcentration of the diluted solutionIn this case, you know:
Ci= 0.197 MVi= 2.42 mLCf= ?Vf= 7.55 mLReplacing 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.
Learn more about dilution:
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Equation between Mg and H2O
Answer:
Mg + 2H2O → Mg(OH)2 + H2, is normally sluggish, but it becomes reasonably rapid when a milled composite of powdered magnesium metal and powdered iron (1−10 mol %) is used with sodium chloride solutions.
Inside the box is a list of endangered animals in the Philippines. Group the animals in three ways and make a diagram of your groupings in the space below.
characteristics of mixtures
Answer:
The mixture has no fixed composition.
To form a mixture energy is neither produced nor evolved.
The mixture has no fixed melting points and boiling points.
the Mixture retains the properties of its components.
Components of mixtures can be separated by simple physical methods.
ANSWER THIS WORKSHEET ALSO I WILL GIVE BRAINIEST
If the statement is true, write true. If the statement is false, change the underlined word
or words to make the statement true.
1. An element’s mass number tells the number of protons in its
nucleus.
2. Negatively charged particles in an atom are called electrons.
3. The cloud model of the atom describes the location of
electrons as specific orbits around the nucleus.
4. Atoms with the same number of protons but different numbers
of neutrons are called isomers.
5. The sum of the protons and neutrons in an atom is called the
atomic number.
6. An object that helps explain ideas about the natural world is
called a model.
Fill in the blank to complete each statement.
7. The positively charged particle of an atom is called a(n) .
8. A particle with no charge is a(n) .
9. A(n) is the particle of an atom that moves rapidly in the
cloudlike region around the nucleus.
10. The tells the number of protons in the
nucleus of every atom of an element.
11. Atoms of the same element that have the same number of protons but different
numbers of neutrons are called .
12. The sum of protons and neutrons in the nucleus of an atom is the
.
Write the letter of the correct answer on the line at the left.
13. The positively charged particle in an atom’s nucleus is the
A electron
B neutron
C proton
D isotope
14. The smallest particle an element can be divided into is the
A electron
B neutron
C isotope
D atom
15. An element’s identity can be determined from its
A atomic number
B number of neutrons
C number of isotopes
D energy levels
16. The model of the atom that described electrons scattered throughout a ball of positive charge was proposed by
A Niels Bohr
B Ernest Rutherford
C J. J. Thomson
D John Dalton
Answer:
5. An element's mass number tells the number of protons in its nucleus.
Atomic
6. Negatively charged particles in an atom are called electrons.
True
7. The cloud model of the atom describes the location of electrons as specific orbits around the nucleus.
Bohr
8. Atoms with the same number of protons but different numbers of neutrons are called isomers.
Isotopes
9. The sum of the protons and neutrons in an atom is called the atomic number.
Mass
10. An object that helps explain ideas about the natural world is called a model.
True
11. Mendeleev arranged his periodic table in order of increasing atomic number.
Mass
12. The rows in the periodic table are called periods.
True
13. Moving across the periodic table from left to right, one finds, in order, metals, then gases, then nonmetals.
Metalloids
14. Another name for a period is a family.
Group
15. On the periodic table, elements in the same column have similar properties.
True
Explanation:
d. Period 3 element with 6 valence electrons
Answer:
Sulfur is an element is Period 3 with 6 valence electrons.
How many protons does silicon have?
28
2
14
28.08
Answer:
14
Explanation:
Can you convert this balanced equation into a nominative equation?
Answer:
yes you can
Explanation:
