True or false..
(A) Burning of magnesium ribbon is physical change

Answers

Answer 1

Answer:

False because it is chemical change

Answer 2
False because it is a chemical change

Related Questions

What is the pH value of lithium chloride?

Answers

Answer:

0.0003

HERE IS YOUR ANSWER

Teniendo en cuenta la imagen anterior responde las siguientes preguntas:

1. ¿Cuál es la tendencia general de la electronegatividad a lo largo de un periodo? a. Aumentar

b. Disminuir

c. La electronegatividad es igual en todos

d. no hay ninguna tendencia

2. Ordene los átomos siguientes de menor a mayor electronegatividad: Li, Ca, C y Se a. Li
b. Se
c. Ca
d. Se
3. ¿Cuál de los átomos siguientes es el que posee mayor potencial de ionización? a. P

b. Sb

c. As

d. N

4. De las siguientes definiciones, ¿Cuál se acerca más a lo que es la electronegatividad? a. Es la tendencia relativa que presenta un elemento a atraer hacia si electrones b. Es la tendencia relativa de un átomo en estado gaseoso a repeler los electrones c. es la carga negativa que representa una unión

d. es la diferencia entre el potencial de ionización y la afinidad electrónica de un elemento. rapido es para hoy

Answers

1. La tendencia general de la electronegatividad durante un período es que la electronegatividad aumenta durante un período

La opción correcta es a. Incremento

Razón

El número de electrones de valencia aumenta durante un período, por lo

que aumentar la tendencia del átomo a lograr la estructura de octeto

estable requiriendo atraer (cada vez menos a medida que avanzamos por

el período desde la izquierda a la derecha) compartieron electrones

cuando se forman enlaces, lo que  aumenta electronegatividad

2. El orden de electronegatividad creciente es Li → Ca → C → Se

Razón

La electronegatividad aumenta a lo largo del período y disminuye en el grupo.

Las ubicaciones de los elementos dados son;

Litio, Li; Grupo 1 período 2 Calcio, Ca; Grupo 2 período 4 Carbono, C; Grupo 14 período 2 Selenio Se; Grupo 16 período 4

Primero escribimos los elementos con los números de grupo más altos,

que son Se y C, después de lo cual tenemos Ca, luego Li, por lo tanto, en

orden creciente, obtenemos;

Li → Ca → C → Se

3. La opción correcta es d. N (nitrógeno)

Razón

El potencial de ionización representa la energía necesaria para eliminar un electrón de un átomo.

El potencial de ionización disminuye en un grupo y aumenta a lo largo de un período de izquierda a derecha.

Tenemos;

Fósforo, P; Grupo 15 período 3 Antimonio, Sb; Grupo 15 período 5 Arsénico, As; Grupo 15 período 4 Nitrógeno, N; Grupo 15 período 2

Por lo tanto, el elemento con mayor potencial de ionización es aquel que se encuentra en la posición más alta en el grupo 15 entre los elementos dados, que es el nitrógeno, N

4. La opción correcta para la definición de electronegatividad es la opción (a);

un. Es la tendencia relativa de un elemento a atraer electrones hacia sí mismo.

Razón

La electronegatividad es la capacidad relativa de un elemento dado para atraer electrones compartidos hacia sí mismo.

Por lo tanto, la opción correcta es a. es la tendencia relativa de un elemento a atraer electrones hacia sí mismo

Obtenga más información sobre la electronegatividad y la energía de ionización aquí;

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What is the molarity of a sodium chloride solution that has 2.0 mol of
sodium chloride dissolved in 0.25 L of water? Answer to two
significant figures.

Answers

Answer:

[tex]\boxed {\boxed {\sf 8.0 \ M \ NaCl}}[/tex]

Explanation:

Molarity is a measure of concentration in moles per liter, therefore the formula is:

[tex]molarity= \frac{moles \ of \ solute}{lites \ of \ solution}[/tex]

There are 2.0 moles of solute or sodium chloride dissolved in 0.25 liters of water or solution.

moles of solute = 2.0 mol NaCl liters of solution = 0.25 L

Substitute these values into the formula.

[tex]molarity= \frac{ 2.0 \ mol \ NaCl}{0.25 \ L}[/tex]

Divide.

[tex]molarity=8 \ mol \ NaCl / L[/tex]

Molarity is measured in molars or M. 1 molar is equal to 1 mole per liter, so our answer is equal to 8 molars.

[tex]molarity= 8 \ M \ NaCl[/tex]

The original measurements of moles and liters have 2 significant figures, so our answer must have the same. For the number we calculated, that is the tenths place. There are no numbers to round, so we add a 0 in the tenths place.

[tex]molarity= 8.0 \ M \ NaCl[/tex]

The molarity of the solution is 8.0 M NaCl.

Identify the product Q in the reaction below
Cl2 +2NaOH ------->NaCL +H2O+Q​

Answers

Answer:

the product of q in the reaction below is Nacl

If a 10.0 g piece of metal required 100 cal to raise its temperature
by 20°C, what would you report as its specific heat?
a. 10 cal/g·°C
b. 200 cal/g·°C
c. 0.5 cal/g·°C
d. 2 cal/g·°C

Answers

Answer:

C. 0.5 cal/g°C

Explanation:

Using the following equation:

Q = m × c × ∆T

Where;

Q = amount of heat absorbed/released (calories)

m = mass of substance (g)

c = specific heat capacity (calg/°C)

∆T = change of temperature (°C)

According to the information provided in this question;

m = 10g

c = ?

∆T = 20°C

Q = 100cal

Using Q = m × c × ∆T

c = Q ÷ (m × ∆T)

c = 100 ÷ (10 × 20)

c = 100 ÷ 200

c = 0.5 cal/g°C

ASAP
The concentration of reactants and products and the rate of reaction were measured during a chemical reaction. After the first 3 seconds, the rate of reaction was 1.8 x10−6 M/s. Which of the following would explain a lower rate after another 3 seconds?

A - The concentration of reactants increased while the concentration of product decreased.
B - The concentration of reactants decreased while the concentration of product increased.
C - All concentrations of reactants and products decreased.
D - All concentrations of reactants and products increased.

Answers

Answer:

B

Explanation:

During the first half of the reaction there was an increase in the rate of reaction due to the high concentration of the reactants. But as the reaction continues we witness a decrease in the amount of reactants which lowers the rate.

Answer:

B.  The concentration of reactants decreased while the concentration of product increased.

Explanation:

took the test :)

Unknown # 21

Flame Test Color: Lilac
Addition of HCl(aq)= NR (No Reaction)
Addition of HCl(aq) and BaCl2(aq)= White precipitate
Addition of HNO3(aq) and AgNO3(aq)= NR (No Reaction)

What is the unknown ionic compund molecular formula?

Answers

Answer is option B
Addictive and always Agn02

15. How many moles of CaCl are in 250. mL of 3.00 M of CaCl solution?
a. 750. mol
b. 1.33 mol
C. 83.3 mol
d. 0.750 mol
e. 3.00 mol

Answers

Answer:D.0.75
Answer d

what is the anode material used in the extraction of aluminium by electrolysis and why it needs to be changed at interval​

Answers

Answer:

the anode material is graphite(replaceable graphite rods).

The oxygen gas burns away the anode as Carbon dioxide therefore the anode must be replaced continuously.

Que. 1. Gallium has 2 naturally occuring Isotopes with mass numbers 69 & 71 respectively. What is the percentage abundance of both Isotopes if their relative atomic mass is equal to 70.59 Amu (Atomic mass Unit)​

Answers

Isotopes are atoms of the same element that have different masses. The relative atomic mass (am) is a weighted average that takes into account the abundance of each isotope. We can calculate the relative atomic mass using the following expression.

[tex]am = \frac{\Sigma m_i \times ab_i}{100}[/tex]

where,

mi: mass of each isotopeabi: percent abundance of each isotope

For Gallium,

[tex]70.59 amu = \frac{69 amu\ x + 71 amu\ y}{100}[/tex]     [1]

where "x" and "y" are the unknown abundances.

We also know that the sum of both abundances must be 100%.

x + y = 100

y = 100 - x   [2]

If we replace [2] in [1], we get

[tex]70.59 amu = \frac{69 amu\ x + 71 amu\ (100-x)}{100} \\7059 amu = -2 amu\ x + 7100amu \\x = 20.5[/tex]

Then, in [2]

y = 100 - x = 100 - 20.5 = 79.5

In conclusion, Ga-69 has an abundance of 20.5% and Ga-71 has an abundance of 79.5%.

You can learn more about isotopes in: https://brainly.com/question/21536220?referrer=searchResults

the metric system of units is known as

Answers

Answer:

International System of Units (SI)

Explanation:

I hope it helps :)

Calculate K for 2CO2(g) ⇔ 2CO(g) + O2(g)
given that the equilibrium concentrations of carbon monoxide, oxygen and carbon dioxide are 2.0 x 10-6 M, 1.0 x 10-6 M, and 0.25 M respectively.

Answers

Explanation:

here's the answer to your question

e) Hydrogen gas is a non-metal and can be prepared in a laboratory Explain why hydrogen gas is collected over water.​

Answers

Answer:

to collect pure hydrogen and avoid mixing with air

A certain amount of NaOH is dissolved in certain kilograms of solvent and molality of the solution is 0.5 m. When the same amount of NaOH is dissolved in 100 grams of less solvent than initial then molality becomes 0.625 m. Determine the amount of NaOH and the initial mass of solvent.​

Answers

[tex]\sf\bold{❍ Given:-}[/tex]

NaOH is dissolved in certain kilograms of solvent and molality of solution 0.5m.

Again , same among of NaOH is dissolved in 100 grams of solvent than initial , then molality becomes 0.625m.

$\space$

Now lets find the amount of NaOH and the initial mass of solvent.

Let,

$\sf\small{Initial\:Mass\:of\:solvent=y}$$\sf\small{Number\:of\:moles\:NaOH\:dissolved=x}$

$\space$

$\sf\bold{ ❍ We\:know,}$

$\sf{Molality(m)=}$ $\sf\dfrac{No.of\:moles\:of\:solute}{No.of\:solvent\:in\:kg}$

$\space$

$\sf\bold{Putting\:the\:formula:-}$

$\space$

$\sf\huge\underline\bold{ ❍Case:1}$

$\space$

$\longmapsto$ $\sf\small{0.5}$ $\sf\dfrac{x}{y}$

$\space$

$\longmapsto$ $\sf{0.5y = x }$

$\space$

$\longmapsto$ $\sf{multiply\:by\:2→ y = 2x}$

$\space$

$\sf\huge\underline\bold{ ❍Case:2}$

$\space$

$\longmapsto$ $\sf\small{0.625}$ $\sf\small\dfrac{x}{y}$ = $\sf\dfrac{x}{y=100g}$

$\space$

$\longmapsto$ $\sf\small{0.625}$ $\sf\dfrac{x}{y-100/1000kg}$ = $\sf\dfrac{x}{y-0.1kg}$

$\space$

$\longmapsto$ $\sf{0.625(y-0.1kg)=x}$

$\space$

$\longmapsto$ $\sf{0.625y-0.0625=x}$

$\space$

$\sf\small\bold{By\:putting\:the\:value\:of \:"x" we\: get:}$

$\space$

$\longmapsto$ $\sf{0.625(2x)-0.0625 = x}$

$\space$

$\longmapsto$ $\sf{1.25x 0.0625 = x}$

$\space$

$\longmapsto$ $\sf{1.25x - x = 0.0625}$

$\space$

$\longmapsto$ $\sf{0.25x = = 0.0625}$

$\space$

$\longmapsto$ $\sf\small{x=}$ $\sf\dfrac{0.0625}{0.25}$= $\sf\bold{x=0.25}$

$\space$

$\sf{So,y=2(x)=2\times0.25=}$ $\sf\bold{y=0.5}$

$\space$

$\sf\small{Initial\:mass\:of\:solvent:0.5kg=500g}$

$\space$

$\sf{Now,}$

Amount of NaOH=

$\space$ $\space$ $\space$ $\space$ $\space$ $\sf{=x\times molar\:mass}$

$\space$ $\space$ $\space$ $\space$ $\space$ $\sf{=0.25\times 40=10}$

$\space$

$\sf\underline{\underline{ ⚘ Hence,amount\:of\:NaOH=10kg}}$

_______________________________

When 4.2 gram of sodium bicarbonate reacts with 10.0 g of acetic acid, the product contains 2.2 g of carbon dioxide and residue cxontaining water and Sodium acetate. The mass of the residue will be:- *

Answers

Na2CO3+2HCl⟶2NaCl+H2O+CO2

Law of conservation of mass- It states that for any closed system, the mass of the system always remain constant over time, as mass of system cannot change. Therefore, (mass of Na2CO3+ mass of HCl) should be equal to (mass of residue + mass of CO2)

Mass of Na2CO3=4.2 g

Mass of HCl=10 g

Mass of residue =12 g

Mass of CO2=2.2 g

∴ Mass of Na2CO3+ Mass of HCl=14.2 g

and Mass of residue + Mass of CO2=14.2 g

Therefore, they follow law of conservation of mass.

What is the energy of a photon that emits a light of
frequency 6.42 x 1014 Hz?
A. 4.67 x 10-19 J
B. 4.25 x 10-19
C. 3.10 x 10-19 J
D. 9.69 x 10-19 J

Answers

Answer:

Option B is correct [4.25 x 10-19J]

Explanation:

Book your exam with us for 100% result

4.78×[tex]10^{-19}[/tex] J  is the energy of a photon that emits light of

frequency 6.42 x[tex]10^{14}[/tex] Hz.

What is the frequency?

Frequency is the rate at which current changes direction per second. The energy of a single photon is given by:

E =hν

where

E is the energy

h is the Planck constant

f is the frequency of the light

The chemical equation for the energy of a photon is given by:

E =hν , where h is the Planck constant and ν is the frequency.

E =hν = 6.626×[tex]10^{-34}[/tex] Js × 7.21×[tex]10^ {14}[/tex]

[tex]s^{-1}[/tex] = 4.78 ×[tex]10^{-19}[/tex] J

Hence, 4.78×[tex]10^{-19}[/tex] J  is the energy of a photon that emits light of

frequency 6.42 x[tex]10^{14}[/tex] Hz.

Learn more about frequency here:

https://brainly.com/question/13040523

#SPJ2

Temperature is measured in what unit?


J

J/goC

J/g

oC

Answers

Temperature is measured in Kelvin..

the pH value of 0.1 mol dm-3 of acid U is 1. Which statement is true about acid U?

A) slightly soluble in water
B) reacts only with a weak alkali
C) the degree of ionization in water is high
D) has a low concentration of hydrogen ions​

Answers

Answer:

the degree of ionization in water is high

Explanation:

The term pH is defined as the negative logarithm of hydrogen ion concentration.

Hence;

pH = -log[H^+]

The pH scale shows the degree of acidity or alkalinity of a solution. A solution of pH 1 is a strong acid. A strong acid dissociates completely in solution.

Hence, acid U has a high degree of ionization in water.

How did elements get to earth?

Answers

the universe formed through the big bang explosion, all of the elements on Earth have been cooked for billions of years in stars and then released in the universe through super- nova explosions.

Choose the answer that is not correct: RER is: Group of answer choices The ratio of carbon dioxide produced to oxygen consumed An indication of the percentage of carbohydrate metabolized An indication of the percentage of lipid metabolized An approximation of kilocalories obtained per liter of oxygen consumed An indication of calories consumed during anaerobic energy production

Answers

Answer:

An indication of calories consumed during anaerobic energy production

Explanation:

RER stands for respiratory exchange ratio, which is the ratio of the volume of carbon dioxide, CO₂, produced to the volume of oxygen, O₂ used in metabolism. RER is used in determining the respiratory quotient during aerobic exercise and rest, from which it can be determined if carbohydrate or fat is the source of fuel consumed in the production of energy for the body through metabolism

Therefore, the answer that is not correct is an indication of calories consumed during anaerobic energy production

Is the following change an oxidation or reduction?

manganese (IV) oxide to manganese (III) oxide.​

Answers

Answer:

12113

Explanation:

step by step:no

steel cranes can carry heavy steel beams thousands of feet high

Answers

Answer:

yes they were made to carry thousands of lb high up

What do Van der Waals forces do?

Answers

Answer:

they are weak forces that attract neutral molecules to one another

Explanation:

particles in liquid or air vibrate and move constantly thus they collide

What are isotopes_???​

Answers

Answer:

Below!

Explanation:

Isotopes are elements with a similar chemical makeup and the same atomic number, but a different atomic mass and number of neutrons . An example of this would be carbon-12, carbon-13, and carbon-14. Three isotopes of the element carbon that have the same 6 protons but have a different neutron count. A simple way to explain isotopes would be to say that they are just different "versions" of an element.

Hope this helps ya! Best of luck <3

Which part of a cell directs the cell's activities and holds its DNA?
A. Mitochondrion
B. Ribosome
C. Nucleus
D. Cell membrane​

Answers

Answer:

Nucleus is the answer

A micrograph of animal cells, showing the nucleus (stained dark red) of each cell. Known as the cell's “command center,” the nucleus is a large organelle that stores the cell's DNA (deoxyribonucleic 

Answer:

nucleus is the part of a cell directs the cells Activities and holds it's DNA

Im sorry if its difficult to read


we dont talk about how I messed up my first question and jad to make another one because im slow​

Answers

Answer:

A ball is thrown straight up from a rooftop 320 feet high. The formula below describes the ball's height above the ground, h, in feet, t seconds after it was thrown. The ball misses the rooftop on its way down and eventually strikes the ground. How long will it take for the ball to hit the ground? Use this information to provide tick marks with appropriate numbers along the horizontal axis in the figure shown.

h=-16t^2+16t+320

Formal charge is calculated by assigning each atom _____ the bonding electrons that it shares. Oxidation number is determined by assigning all the shared electrons of a particular bond to the atom with the _____ electronegativity. Multiple choice question. half; higher half; lower all; lower all; higher

Answers

Answer:

A). half, higher

Explanation:

The Formal charge is elaborated as the 'allocated charge to a molecules' atom' on the basis of the assumption that the electrons present in the chemical bond are equally split among the atoms. It is estimated by 'halving the no. of bonding electrons that encircle the atom.

While Oxidation number is characterized as the 'hypothetical charge of an atom that is present within a molecule.' It is also defined as 'the actual number of lost or gained electrons or the rate at which the electrons are gained or lost by an atom to develop a chemical bond along with the other atom.' It is calculated by allocating or sharing the electrons having the higher electronegativity belonging to a specific bond with the other. Thus, option A is the correct answer.

Write down a step by step process of finding the volume of CO₂ produced during the fermentation of C₆H₁₂O₆ at STP.

Answers

Answer:

Step 1: Write a balanced chemical equation of the reaction

Step 2: Convert the mass of glucose given to moles of glucose by dividing with the molar mass of glucose, 180 g/mol:

Step 3: Using the mole ratio in the equation of reaction, determine the moles of CO₂ produced:

Step 4: Convert moles of CO₂ to volume in litres of CO₂ at STP:

Explanation:

Fermentation is a complex chemical process whereby microorganisms such as yeast are used in converting carbohydrates such as glucose into ethanol and carbon dioxide under anaerobic conditions:

Step 1: Write a balanced chemical equation of the reaction

Theequation of the fermentation of glucose, C₆H₁₂O₆ at STP is as follows:

C₆H₁₂O₆ (aq) ----> 2 C₂H₅OH (l) + 2 CO₂ (g)

Step 2: Convert the mass of glucose given to moles of glucose by dividing with the molar mass of glucose, 180 g/mol:

Moles of glucose = mass of glucose given/molar mass of glucose = x g/ 1180 g/ mol = x moles of glucose

Step 3: Using the mole ratio in the equation of reaction, determine the moles of CO₂ produced:

From the equation of reaction, 1 mole of C₆H₁₂O₆ produces 2 moles of CO₂.

Therefore, x moles of C₆H₁₂O₆ will produce 2x moles of CO₂

Step 4: Convert moles of CO₂ to volume in litres of CO₂ at STP:

1 mole of a gas at STP has a volume of 22.4 L

1 mole of CO₂ has a volume of 22.4 L

2x moles of CO₂ has a volume of 2x × 22.4 L

Which of the following materials contains a base?

a. Stomach digestive juices
b. Orange juice
c. Ammonia window cleaner
d. Vinegar

Answers

Answer:

c. ammonia window cleaner

Explanation:

Window cleaners contain ammonia (a base) for the purpose of removing the dust and grease on the windows.

digestive juices, orange(a citrus) juice, and vinegar are all highly acidic.

... give me brainliest please :)) ...

balance chemical reaction of oxalic acid with conc. sulphuric acid​

Answers

Answer:

Explanation: since oxalic acid is a weak acid it wont provide a strong acidic medium. So in order to provide a strong acidic medium dilute sulphuric acid is added.

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