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wariber [46]
3 years ago
13

When someone’s immune system overreacts to something harmless it’s called:

Chemistry
2 answers:
ruslelena [56]3 years ago
5 0
I feel like it would be c
Mama L [17]3 years ago
3 0
The answer to this question is C. An allergy.
You might be interested in
Be sure to answer all parts.
Fudgin [204]

Answer:

2H₂ + O₂       →     2H₂O

Explanation:

Chemical equation:

H₂ + O₂       →     H₂O

Balance chemical equation:

2H₂ + O₂       →     2H₂O

Step 1:

H₂ + O₂       →     H₂O

Left hand side                     Right hand side

H = 2                                    H = 2

O = 2                                    O = 1

Step 2:

H₂ + O₂       →     2H₂O

Left hand side                     Right hand side

H = 2                                    H = 4

O = 2                                    O = 2

Step 3:

2H₂ + O₂       →     2H₂O

Left hand side                     Right hand side

H = 4                                    H = 4

O = 2                                    O = 2

7 0
3 years ago
HELP ILL MARK BRAINLIEST
exis [7]

Answer:

Formation. Main-sequence stars, including the sun, form from clouds of dust and gas drawn together by gravity. ... The core that is left behind will be a white dwarf, a husk of a star in which no hydrogen fusion occurs. Smaller stars, such as red dwarfs, don't make it to the red giant state.

Explanation:

4 0
3 years ago
which of the following correctly identifies the composition of an oxygen atom? A.8 protons, 8 electrons, and 8 neutrons. B.6 pro
Ulleksa [173]
<span>You can answer this question by getting the atomic number and atomic mass of Oxygen from a periodic table. There you will find that the atomic number is 8, that means, by definition, that it has 8 protons. This is, because atomic number is defined as the number of protons of an element. Given that the atom is neutral, that implies that the atoms have the same number of electrons than protons. So you already know that the oxygen atoms has 8 protons and 8 electrons. The number of neutrons can vary, which is what defines the isotopes. Given that the atomic mass of oxygen is 15.999, that means that most atoms of oxygen has 8 neutrons (8 protons +8 neutrons = 16 atomic mass). But you can not be sure that a specific atom of oxygen has 8 neutrons, nevertheless, given that the other options are discarded (because they do not have 8 protons and 8 electrons), the only correct answer is the option A. 8 protons, 8 electrons, and 8 neutrons.</span>
8 0
3 years ago
Read 2 more answers
La aspirina se prepara haciendo reaccionar ácido salicílico con exceso de anhídrido etanoico. En un experimento, 50.05 g de ácid
Tanya [424]

La aspirina se prepara haciendo reaccionar ácido salicílico con exceso de anhídrido etanoico. En un experimento, 50.05 g de ácido salicílico se convirtieron en 55.45 g de aspirina. ¿Cuál fue el porcentaje de rendimiento?

<em>In English:</em>

Aspirin is prepared by reacting salicylic acid with excess ethanoic anhydride. In one experiment, 50.05 g of salicylic acid was converted to 55.45 g of aspirin. What was the yield percentage?

Answer:

el rendimiento porcentual para la cantidad dada de ácido salicílico es 84.99 %

<em>In English:</em>

<em>the percent yield for the given amount of salicylic acid is </em><em>84.99%</em>

<em></em>

Explanation:

La ecuación química equilibrada para la reacción se puede escribir como:

C₇H₆O₃ + C₄H₆O₃    →    C₉H₈O₄ + HC₂H₃O₂

Para la reacción mostrada arriba; El reactivo limitante de la reacción es el ácido salicílico. Ahora; calcular el porcentaje de rendimiento; se espera que primero determinemos el rendimiento teórico de la reacción.

Entonces; la fórmula para calcular el porcentaje de rendimiento: \mathbf {= \frac{actual \ yield }{theoretical \ yield } *100 }  

El rendimiento teórico se determina de la siguiente manera:

50.05 g * 1 mol / 138.21 g / mol de C₇H₆O₃ * 1 mol de C₉H₈O₄ / 1 mol de C₇H₆O₃ * 180.157 g / mol de C₉H₈O₄ = 65.24 g de C₉H₈O₄

Porcentaje de rendimiento \mathbf {= \frac{55.45 }{65.24 } *100 }

Porcentaje de rendimiento = 84.99%

Por lo tanto, el porcentaje de rendimiento para la cantidad dada de ácido salicílico es 84.99%

<em>In English:</em>

<em>The balanced chemical eqaution for the reaction can be written as:</em>

<em>C₇H₆O₃ + C₄H₆O₃    →    C₉H₈O₄ + HC₂H₃O₂</em>

<em>For the reaction shown above;  The limiting reactant from the reaction is  salicylic acid. Now; to calculate the percentage yield ; we are expected to first determine the theoretical yield of the reaction. </em>

<em>So; the formula for calculating the percentage yield </em>\mathbf {= \frac{actual \ yield }{theoretical \ yield } *100 }<em>  </em>

<em />

<em>The theoretical yield is determined as follows:</em>

<em>50.05 g * 1 mol/ 138.21 g/mol of C₇H₆O₃ * 1 mol of C₉H₈O₄/ 1 mol of C₇H₆O₃ * 180.157 g/mol of C₉H₈O₄ = 65.24 g of C₉H₈O₄ is produced</em>

<em />

<em>Percentage yield </em>\mathbf {= \frac{55.45 }{65.24 } *100 }<em />

<em>Percentage yield = 84.99%</em>

<em />

<em>Thus, the percent yield for the given amount of salicylic acid is </em><em>84.99%</em>

7 0
3 years ago
What element has an r.m.m of 72​
igomit [66]

Answer:

Germanium

Explanation:

The element Germanium is one with a relative molecular mass of 72. This corresponds to the mass number of this element.

Relative molecular mass of an element is the mass of a formula unit to that of a carbon-12 atom.

The chemical symbol of Germanium is Ge. It is a lustrous and hard metalloid belonging to the carbon group.

It was discovered by Clemens Alexander Winkler.

7 0
3 years ago
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