Answer:
Physical changes are changes that do not alter the identity of a substance. Chemical changes are changes that occur when one substance is turned into another substance.
Explanation:
Una reacción química es un proceso en el cual se produce un cambio químico, es decir, se consume una o más sustancias a medida que se forman una o más sustancias nuevas.
Answer:
Para ser mas exactos una reaccion quimica es donde los reactivos se transforman en productos.
Explanation:
Durante las reacciones quimicas, ocurren ciertas transformaciones que hace que se tome o se libere energia del medio, generando que los reactivos de la reaccion, es decir los compuestos iniciales, en un determinado espacio y tiempo bajo ciertas condiciones de presion y temperatura exactas se transformen en productos.
Para la quimica, la misma cantidad de materia que se encuentra en los reactivos se mantendra en los productos, es por eso que cada reaccion quimica debe respetar las reglas de la estequiometria y estar balanceadas a la perfeccion.
Which of the following best describes an electron transition?
A. An electron gains or loses energy and moves between continuous
energy levels.
B. An electron gains or loses charge and changes into a proton or a
neutron.
C. An electron gains or loses energy and moves between quantized
energy levels.
D. An atom gains or loses an electron and becomes an ion.
Answer:
A. An electron gains or loses energy and moves between continuous
energy levels.
Briefly explain why adding insulation to an attic helps reduce heating costs.
Answer:
Insulation reduces the exchange of heat through a surface such as a wall, attic, duct or roof. In a well-insulated home, less warm air escapes from the house during the winter, and less cool air escapes during the summer, reducing the amount of energy needed for heating and cooling
Find the surface area of a square pyramid with side length 5 cm and slant height 4 cm.
Answer:
h = height
s = slant height
a = side length
P = perimeter of base
e = lateral edge length
r = a/2
V = volume
L = lateral surface area
B = base surface area
A = total surface area
Explanation:
Volume of a square pyramid:
V = (1/3)a2h
Slant Height of a square pyramid:
By the pythagorean theorem we know that
s2 = r2 + h2
since r = a/2
s2 = (1/4)a2 + h2, and
s = √(h2 + (1/4)a2)
This is also the height of a triangle side
Lateral Surface Area of a square pyramid (4 isosceles triangles):
For the isosceles triangle Area = (1/2)Base x Height. Our base is side length a and for this calculation our height for the triangle is slant height s. With 4 sides we need to multiply by 4.
L = 4 x (1/2)as = 2as = 2a√(h2 + (1/4)a2)
Squaring the 2 to get it back inside the radical,
L = a√(a2 + 4h2)
Base Surface Area of a square pyramid (square):
B = a2
Total Surface Area of a square pyramid:
A = L + B = a2 + a√(a2 + 4h2))
A = a(a + √(a2 + 4h2))
What happens when an unstable nucleus undergoes radioactive decay?
A. Electrons change energy levels to balance the nucleus.
B. Energy is absorbed by the nucleus to make it more stable.
O C. Particles or electromagnetic radiation are emitted.
D. The nucleus increases in mass through radioactive decay.
Can anyone solve this for me please.
I appreciate anyone that is helping me with these questions
How many moles of sodium are in its 85 g?
Answer:
22.98977
Explanation:
don't worry about that
Explanation:
85 g Na × (1 mol Na/22.9898 g Na)
= 3.7 mol Na
A solution (HELP ASSAAAAP ROAD TO GRADUATION)
Question 7 options:
A)
can contain more than two phases.
B)
must contain water.
C)
is always a liquid.
D)
is a single-phase homogeneous mixture.
Hey there! A simple explanation is below.
Answer:
D) is a single phase homogeneous mixture.
Explanation:
A solution is a form of homogenous combination made up of two or more components in chemistry. A solute is a material that is dissolved in another material, known as a solvent, in such a combination. The mixing of a solution takes place at a scale where the effects of chemical polarity are present, resulting in solvation-specific interactions. In most cases, the solution is in the condition of the solvent, because it is most common in the mixture.
Which is the best reason to carry out scientific research on climate change?
A. To help people prepare for the future
O B. To create jobs for scientists
C. To elect better-informed politicians
D. To win political debates
Which is the best reason to carry out scientific research on climate change?
A. To help people prepare for the future
B.To create jobs for scientists ☑️C. To elect better-informed politicians
D. To win political debates
Answer:
to create jobs for scientists
Which of the following could possibly be true about a strong acid? (Check all that apply:).
It will completely dissociate (break apart) when dissolved in water.
It could have a pH of 6
It could have a pH of 13
Only a few of the acid molecules will dissociate (break apart).
It could have a pH of 2.
It could have a pH of 9
Answer:
it could have a pH of 2 it will completely dissociate when dissolved in waterWhich of the following correctly ranks the following bonds in order from most to least polar?
C-H, N-H, O-H, F-H
a)
O-H > F-H > N-H > C-H
b)
F-H > N-H > O-H > C-H
c)
C-H > N-H > O-H > F-H
d)
F-H > O-H > N-H > C-H
Answer:
O-H F-H N-Hy
Explanation:
C-H N-H O-H F-H
WHAT HAPPENS WHEN ELECTRIC CURRENT PASSES THROUGH ACIDIFIED WATER.
Answer:
When an electric current is passed through acidified water, it decomposes to give hydrogen and oxygen gas. The hydrogen gas is obtained at the cathode and the oxygen gas is obtained at the anode
Sodium-22 has a 2.605-year half-life. If you begin with 1.570 grams of Na-22, how many grams are left after 1.00 year?
Type the correct answer in the box. Express your answer to the correct number of significant figures.
Answer:
1.20 grams
Explanation:
Correct on edmentum/plato
Answer: 1.20 grams
Explanation:
How are liquid water, ice, water different from each other?
Answer: In liquid water, water molecules are moving faster. They are still close together, but they are no longer stuck in a rigid pattern as they are in ice. Water molecules in liquid water are constantly sliding past and bumping into each other; they keep moving from one place to another.
Answer:
they are different forms
Explanation:
ice is solid
and water is liquid
they also have different densities
A 25 Ω resistor has a voltage drop of 12 V across it. Calculate the current flowing through the resistor
Answer:
0.48
Explanation:
[tex]i = \frac{v}{r} [/tex]
because we are looking for I which is current we say
I = 12÷25 which is 0.48.
The current flowing through the resistor is 0.48 A.
What is resistor?The resistor is a length of wire which resists the flow of current.
According to Ohm's law, the potential difference is proportional to the current flowing in the circuit.
V =I R where R is the resistance.
Given is the resistance of resistor R = 25Ω and the voltage drop V =12 Volt, then the current through the resistor will be
I =V/R
I = 12/25
I =0.48 A
Thus, the current in resistor is 0.48 Amperes.
Learn more about resistor.
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4. What is a renewable resource? List some examples.
Answer:
Renewable resources include biomass energy (such as ethanol), hydropower, geothermal power, wind energy, and solar energy. Biomass refers to organic material from plants or animals. This includes wood, sewage, and ethanol (which comes from corn or other plants).
five examples of renewable resources
Solar energy.
Wind energy.
Geothermal energy.
Hydropower.
Bioenergy.
I hope it help you
Answer:
The most popular renewable energy sources
currently are
Solar energy
Wind energy
Hydro energy
Tidal energy
Geothermal energy
Biomass energy
calculate the molecular weight of CaCO3.
Answer:
Explanation:
CaCO3 = 1*Ca + 1*C + 3*O
=1*40 + 1*12 + 3*16
=40 + 12 + 48
=100 amu
Which defines the word planet?
A. A large body that revolves around the Moon.
B. A large body suitable for life.
C. A large body that contains water and land.
D. A large body that revolves around the Sun.
Answer:
I think it's D cause one of the requirements for a planet is that it has to revolve around a star
Chemistry 1 question please help!! 10 points
Answer:
3
Explanation:
its the 3 one it is
What is the pH of a solution?
O A. A measure of the strength of the acid
B. A measure of the buffering ability of the solution
O c. A measure of the hydrogen gas concentration
O D. A measure of the acidity of the solution
Answer:
D. A measure of the acidity of the solution
Explanation:
pH is a measure of how acidic or basic a solution is, and is measured on a scale from 0-14, where 7 is neutral, anything less than 7 is acidic, and anything more than 7 is basic.
The metric system is also known as the
Answer:
THE answer is all of above
Explanation:
During nuclear fission and fusion, what is matter that seems to disappear actually converted into?
mass
energy
volume
nuclei
Answer:
The Correct Answer is " Energy"
Goodluck Guys
Explanation:
During nuclear fission and fusion, what is matter that seems to disappear actually converted into energy and the correct option is option 2.
What is Nuclear fission and Fusion?
here are two types of nuclear reactions called nuclear fission and nuclear fusion. These nuclear reactions involve the disintegration and combination of the elemental nucleus.
Nuclear fission refers to the breaking or splitting of a large or parent atom into smaller ones, or two or more daughter atoms.
The term 'nuclear fusion' refers to the process by which two or more atoms combine to form a larger atom. The nuclear fusion process is endothermic because it requires absorbing energy to fuse two atoms.
Both fission and fusion are nuclear reactions that produce energy.
Therefore, During nuclear fission and fusion, what is matter that seems to disappear actually converted into energy and the correct option is option 2.
Learn more about Nuclear fission and fusion, here:
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Calculate the mass of hydrogen in 250 grams of C2H6
Answer:
50.28 grams
Explanation:
hope this helps
Which two laws were discovered by Antoine Lavoisier and Joseph Proust?
Por qué razón se fomenta la inmigración Europea?
Hola aquí va la respuesta!
Se fomentó la inmigración europea porque la economía no era buena y vinieron a Paraguay para mejorar su situación.
Hola aquí va la respuesta!
Se fomentó la inmigración europea porque la economía no era buena y vinieron a Paraguay para mejorar su situación.
If the pH = 6.5, what is the [H+]? *
3.16 x 10-7
3.16 x 10-6
O
3.16 x 10-5
Answer:
Key Concepts
The hydrogen ion concentration in a solution, [H+], in mol L-1, can be calculated if the pH of the solution is known.
pH is defined as the negative logarithm (to base 10) of the hydrogen ion concentration in mol L-1 pH = -log10[H+] ...
[H+] in mol L-1 can be calculated using the equation (formula): [H+] = 10-pH
More items...
Explanation:
Answer:
[tex]pH = - log[H {}^{ + } ] \\ 6.5 = - log[H {}^{ + } ] \\ [H {}^{ + } ] = {10}^{ - 6.5} \\ [H {}^{ + } ] = 3.16 \times {10}^{ - 7} \: mol {dm}^{ - 3} [/tex]
1. _C2H5OH + _O2 = _CO2 + _H2O
2. _Zn + _CuSO4 = _ZnSO4 + _Cu
3. _Ca + _AICI = _CaCl2 + _Al
4. _Hg(OH)2 + _H3PO4 = _Hg3(PO4)2 + _H20
5. _H3PO3 +_H3PO4 + _PH3
6. _C25H52 + _O2 = _CO2 + _H20
7. _Au2O3 = _Au + _O₂
8. _KBr + _Cl2 = _KCI + _Br2
9. _C4H10 + _O₂ = CO₂+ _H₂O
10. P4 + O2 = P₂O5
Answer:1. Ethanol + Dioxygen = Carbon Dioxide + Water
Explanation:
Suppose that we combined 75 g of magnesium with 45 g of nitrogen and heat them up. Predict the product of
the reaction, determine the limiting reactant, and calculate the theoretical yield.
Answer:
Mg is the limiting reactant
The theoretical yield is 105.2 g of Mg3N2
Explanation:
3Mg(s) + N2(g) -----> Mg3N2(s)
Number of moles of Mg = 75g/24g/mol = 3.125 moles
3 moles of Mg yields 1 mole of Mg3N2
3.125 moles of Mg yields 3.125 × 1/3 = 1.042 moles of Mg3N2
Number of moles of N2 = 45g/28g/mol = 1.607 moles
1 mole of N2 yields 1 mole of Mg3N2
1.607 moles of N2 yields 1.607 moles Mg3N2
Hence, Mg is the limiting reactant
The theoretical yield of Mg3N2 = 1.042 moles of Mg3N2 × 101 g/mol = 105.2 g of Mg3N2
How much heat is required to raise the temperature of 20.0g of ice from-12°C to 0°C?
Answer:
https://socratic.org/questions/how-much-heat-is-required-to-convert-5-88-g-of-ice-at-12-0-c-to-water-at-25-0-c-
Explanation:
Consider the following intermediate chemical equations.
CH2(g) →C(s) + 2H2(g)
CC1.(g) → C(s) +2012(g)
H2(g) +C12(g) → 2HCl(9)
ΔH, = 74.6 kJ
ΔH2 = 95.7 kJ
ΔΗ =
ΔHg =-92.3 kJ
What is the enthalpy of the overall chemical reaction CH (g) +4012(g) → CCl4(h)+ 4HCl(g)?
Answer: The enthalpy of the overall chemical equation is -205.7 kJ
Explanation:
Hess's law is defined as the law which states that the total amount of heat absorbed or released for a given chemical reaction will remain the same whether the process occurs in one step or several steps.
In this law, a chemical equation is treated as an ordinary algebraic expression that can be added or subtracted to yield the required overall equation.
The enthalpy change or heat of the overall reaction is the summation of the enthalpies or heats of the intermediate reactions involved in the process.
The given overall chemical equation follows:
[tex]CH_4(g)+4Cl_2(g)\rightarrow CCl_4(g)+4HCl(g);\Delta H^o_{rxn}[/tex]
The intermediate equations for the above reaction are:
(1) [tex]CH_4(g)\rightarrow C(s)+2H_2(g);\Delta H_1=74.6 kJ[/tex]
(2) [tex]CCl_4(g)\rightarrow C(s)+2Cl_2(g);\Delta H_2=95.7kJ[/tex]
(3) [tex]H_2(g)+Cl_2(g)\rightarrow 2HCl(g);\Delta H_3=-92.3kJ[/tex]
According to Hess law, the enthalpy of the reaction becomes:
[tex]\Delta H^o_{rxn}=[1\times (\Delta H_1)] + [1\times (-\Delta H_2)] + [2\times (\Delta H_3)][/tex]
Putting values in above expression, we get:
[tex]\Delta H^o_{rxn}=[1\times (74.6)] + [1\times (-95.7)] + [2\times (-92.3)]\\\\\Delta H^o_{rxn}=-205.7kJ[/tex]
Hence, the enthalpy of the overall chemical equation is -205.7 kJ
