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Alexandra [31]
3 years ago
7

Jose and Sarah are running in the cross country meet. Their skeletal and muscular systems work to move them through the course.

As they run, they breathe faster and harder and their heart rate increases.
Chemistry
1 answer:
Inessa [10]3 years ago
5 0

Answer: Jose and Sarah are running in the cross country meet. Their skeletal and muscular systems work to move them through the course. As they run, they breathe faster and harder and their heart rate increases.

A.work together

Explanation:This should help:)

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Sasha did an experiment to study the solubility of two substances. She poured 100 mL of water at 20 °C into each of two beakers
amm1812

Answer:

A

Explanation:

The solubility of a substance is directly proportional to the temperature. It means that solubility will increase with the increases in temperature. At higher temperature, the kinetic energy increased that allow the solvent molecules to break the solute particles more effectively.

Substance A has a higher solubility because the weight of substance A measured at the end of the experiment is less than the weight of substance B.

Hence, the correct answer is A.

8 0
3 years ago
Match the following associations. Exothermic or endothermic
Alekssandra [29.7K]

<u>Answer:</u>

<em>1) ∆H is positive \Rightarrow Endothermic </em>

<em>2) E_p>E_r \Rightarrow Endothermic  </em>

<em>3) Energy is absorbed \Rightarrow Endothermic </em>

<em>4) E_r>E_p \Rightarrow Exothermic </em>

<em>5) ∆H is negtive \Rightarrow Exothermic </em>

<em></em>

<u>Explanation:</u>

∆H is called as enthalpy change  

It is also called as Heat of reaction

Energy is required for the bond to break a bond.

Energy is released when a bond is formed.

H_2+Cl_2>2HCl

that is

H-H+Cl-Cl>2H-Cl

We see in this equation, bonds between hydrogen and chlorine molecules gets broken and on the right side bond is formed in HCl.

If energy of products greater than energy of reactants then the reaction enthalpy change is endothermic .

If energy of products lesser than energy of reactants then the reaction enthalpy change is exothermic .

For example  

\Delta H=E_p-E_r

=30KJ-20KJ

=+10KJ

(positive hence endothermic)

\Delta H=E_p-E_r

=10KJ-40KJ

=-30KJ

(negative hence exothermic)

8 0
3 years ago
The table below shows the number of sub-atomic particles in an atom of sodium. Sub-atomic Particles Sub-atomic Particle Number P
AlexFokin [52]

Answer is: the amu of a sodium atom is 23.

The unified atomic mass unit (amu) is a standard unit of atom mass.

One unified atomic mass unit is approximately the mass of one nucleon (proton or neutron).

The unified atomic mass unit is equal 1.66·10⁻²⁷ kg.

n(p⁺) = 11; number of protons in sodium atom.

n(n°) = 12; number of neutrons of sodium atom.

n(p⁺ + n°) = 11 + 12.

n(p⁺ + n°) = 23; number of nucleons in sodium atom.

5 0
3 years ago
Read 2 more answers
Which reaction should be used to convert propene into an alkyl halide?
skelet666 [1.2K]
Substitution that is it 
4 0
3 years ago
Read 2 more answers
Is iornIInitrate ionic or covalent
kondaur [170]

Answer:

Iron (II) nitrate is ionic compound

Explanation:

Formula:

Fe(NO₃)₂

Iron (II) nitrate is ionic compound.

Its molecular mass is 179.85 g/mol.

NO⁻₃ is anion while Fe⁺² is cation.

Iron loses its two electron which is accepted by nitrate.

Its molecular formula can be written as FeN₂O₆.

Its color is pale green.

Its melting point is 333.65 K.

It is para magnetic compound.

it is mostly present in non hydrated form.

It is also known as ferric nitrate.

It is used to form sodium amide.

Its is also used catalyst.

7 0
3 years ago
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