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tatyana61 [14]
3 years ago
8

Which event always involves a chemical change?

Chemistry
1 answer:
TEA [102]3 years ago
6 0

Answer:

<h2><u><em>Burning</em></u></h2>

Explanation:

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Calculate the gravitational force of attraction between a 26kg boy and his 5.1kg dog when they are separated by 0.19m
Pavel [41]

Answer:

Gravitational force of attraction G(f) = 2.44 x 10⁻⁷ (approx.)

Explanation:

Given:

Mass M1 = 26 kg

Mass M2 = 5.1 kg

Distance r = 0.19 m

Find:

Gravitational force of attraction G(f)

Computation:

Gravitational force of attraction G(f) = G(m1)(m2)/r²

Gravitational force of attraction G(f) = [6.67 x 10⁻¹¹](26)(5.1)/(0.19)²

Gravitational force of attraction G(f) = 8.84 x 10⁻⁹ / 0.0361

Gravitational force of attraction G(f) = 2.44 x 10⁻⁷ (approx.)

6 0
3 years ago
Ammonia is produced by the Haber process. The equation is shown.
choli [55]

Answer:

option D

Explanation:

Increasing the temperature increases the yield of ammonia and speeds up the reaction as chemical reaction is affected by temperature.

7 0
2 years ago
Read 2 more answers
The density of Mg is 1.74g/cm3. The density of strontium is 2.60g/cm3. What would you expect the density of Ca to be?
Tomtit [17]

The density of Ca will be between that of Mg and Sr

Explanation:

Ca, Mg and Sr are group II elements. They are called alkali earth metals. The correct order of the elements in this group are: Be, Mg, Ca, Sr, Ba and Ra.

Density is an intensive property of matter which describes the amount of matter(mass) per volume of a substance.

  • Density varies proportionally with mass. The higher the mass, the higher its density.
  • On the periodic table, atomic mass which the number of protons and neutrons in the nucleus of an atom increases down the group.
  • This implies a progradation in the value of density down the group. Therefore one expects that the value of density of Ca will fall between that of Mg and Sr. It cannot be more than 2.6g/cm³ nor less than 1.74g/cm³.

Learn more:

density brainly.com/question/2658982

mass number brainly.com/question/2597088

#learnwithBrainly

                   

6 0
3 years ago
Write a chemical equation of Dr. Jeff’s demonstration using a battery to light steel wool on fire. The battery is used to allow
Elis [28]

Answer:

2Fe(s) + 3O2(g) --------> 2FeO3(s)

Explanation:

According to the question, a  battery was used  to light the steel wool by bringing the terminals very close together. When  the battery came into contact with the steel wool, current was sent out through the thin wire.  This caused the iron to heat up quite well.

Iron reacts with oxygen under these conditions as follows;

2Fe(s) + 3O2(g) --------> 2FeO3(s)

This is the chemical reaction that occurs when the steel wool is set on fire.

6 0
3 years ago
If 15 g of C₂H₆ reacts with 60.0 g of O₂, how many moles of water (H₂O) will be produced?
IceJOKER [234]

Answer:

n_{H_2O}=1.5molH_2O

Explanation:

Hello,

In this case, the undergoing chemical reaction is:

2C_2H_6 + 7O_2 \rightarrow 4CO_2 + 6H_2O

Next, we identify the limiting reactant by computing the available moles of ethane and the moles of ethane consumed by 60.0 grams of oxygen:

n_{C_2H_6}^{available}=15g*\frac{1mol}{30g} =0.50molC_2H_6\\n_{C_2H_6}^{reacted}=60.0gO_2*\frac{1molO_2}{32gO_2}*\frac{2molC_2H_6}{7molO_2} =0.536molC_2H_6

Thus, we notice there are less available moles, for that reason, the ethane is the limiting reactant. Finally, we can compute the produced moles of water by:

n_{H_2O}=0.50molC_2H_6*\frac{6molH_2O}{2molC_2H_6}\\\\n_{H_2O}=1.5molH_2O

Best regards.

5 0
3 years ago
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