For each item, choose whether the change is a physical change or a chemical change.
exploding firecracker:
mowing grass:
breaking a window:
spreading butter on toast:
burning wood in a fireplace:
acid rain corroding gravestones:

Answer:

14.40g of H2

Explanation:

The balanced equation for the reaction is given below:

B2H6(g) + 6H2O(l) → 2H3BO3(s) + 6H2(g)

Next, we shall determine the mass of B2H6 that reacted and the mass of H2 produced from the balanced equation. This is illustrated below:

Molar mass of B2H6 = (2x11) + (6x1) = 28g/mol

Mass of B2H6 from the balanced equation = 1 x 28 = 28g

Molar mass of H2 = 2x1 = 2g/mol

Mass of H2 from the balanced equation = 6 x 2 = 12g

From the balanced equation above,

28g of B2H6 reacted to produce 12g of H2.

Finally, we shall determine the mass of H2 produced when 33.61g of B2H6 reacted with excess water. This can be obtained as follow:

From the balanced equation above,

28g of B2H6 reacted to produce 12g of H2.

Therefore, 33.61g of B2H6 will react to produce = (33.61 x 12)/28 = 14.40g of H2.

Therefore, 14.40g of H2 were produced from the reaction.

Answer:

3.5 g CO2

Explanation:

A hummingbird emits up to 3.5 grams of CO2 a day.

Equation:7.9 x 10‒2mol CO2x (44.01 g CO2/ 1 mol CO2)

=3.5 grams

Hope this helps!

Answer:

The electron configuration for zinc is 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰. To find electron configuration, simply follow the periodic table from top to bottom, left to right (basically increasing atomic number) until you reach the element you are looking for.

Answer:B

Explanation:

TOOK DA TEST

As the firework releases heat, it is considered as exothermic reaction. The correct option is B.

An exothermic reaction is one in which the energy required to break bonds in the reactants is less than the energy released when new bonds form in the products.

Energy is constantly released during an exothermic reaction, often in the form of heat. Exothermic reactions characterize all combustion reactions.

Endothermic reactions are chemical reactions that produce products by absorbing heat energy from their surroundings.

Exothermic reactions are important in forensic science, particularly in the investigation of fires and explosions.

Endothermic refers to a chemical reaction that requires heat and results in cooling of the surroundings.

As fireworks are releasing energy in the form of heat, it can be called as an exothermic reaction.

Thus, the correct option is B.

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Answer:

They could cause an organism and population and species to die.

Explanation:

If the asteroid hits on ground, there would be a colossal amount of dust thrown up into the atmosphere and our world. If it hits in water and ocean , then there would be a huge surge in water vapor in the atmosphere. This would result in an increase in rain resulting in landslides and mudslides

Answer:

Polar Zones - Coldest Temperature

Temperate Zones - Moderate Temperature

Tropical Zones - Hottest Temperature

Explanation:

The closer you are to the Equator, the hotter it gets, as the sun hits the middle of the Earth the most. At the poles, the sun hits it there the least, so it is the coldest. In between, we would have a mild between hot and cold.

*Remember that the Earth is at a tilt, and that is why we have seasons and why the Equator is so hot and the Poles are so cold.

Answer:

I answered the question on edmentum and that person was correct.

Explanation:

The polar zone is the coldest because the Sun’s rays hit this part of Earth at a wide angle, causing their energy to be spread thinly over a large surface area.

The topical zone is the hottest because the Sun’s rays hit this part of Earth nearly straight on, focusing the heat on a small surface area.

The temperate zone experiences moderate temperatures because the Sun’s rays hit this zone at an angle that concentrates the heat on a surface area that is smaller than on the polar zone and larger than on the tropical zone.

Answer:

O chemical change  because a temperature change was observed, which indicated that the water

Explanation:

I have taken this class

Answer: Change in a single nitrogen base in the DNA sequence will not have any significant effect on the organism.

So A

Explanation:

This is known as point mutation and it does not have any significant change in the protein and it is least harmful type of DNA mutation.

Answer:

0° Celsius

Explanation:

The thermometer shows 0° Celsius which corresponds to 32° F.

Answer:

0 degrees celsius

Explanation:

just did the test

Answer:

answer is A. a saturated hydrocarbon that has more than 35 carbons in its chain

Explanation:

edge in 2020 :)

The compound which is used to make asphalt is a saturated hydrocarbon that has more than 35 carbons in its chain.

Asphalt is also known by the name of bitumen, its appearance is sticky and black or present in semi solid form of petroleum.

Asphalt is a kind of hydrocarbon means mainly formed by the composition of carbon atoms and hydrogen atoms, but in very trace quantity amount of nitrogen, sulfur and other hateroatoms are also present. It is present in complex form means both saturated and unsaturated or aliphatic and aromatic compounds are present in it. It is formed by the long carbon chain which has a number of Carbon atoms around 150.

Hence it is a saturated hydrocarbon that has more than 35 carbons.

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Answer:

B. Alpha

Explanation:

Alpha decays always split into an element and He.

Beta decays always split into an element and e- (eletrons).

Gamma decays always split into an element and radiation.

Answer : The formula for each of the following is:

(a) [tex]C_{22}H_{46}[/tex]

(b) [tex]C_{17}H_{34}[/tex]

(c) [tex]C_{13}H_{24}[/tex]

Explanation :

The general formula of alkanes is [tex]C_n H_{2n+2}[/tex] where n is the number of the carbon atoms present in a molecule of alkane.

The general formula of alkenes is [tex]C_n H_{2n}[/tex] where n is the number of the carbon atoms present in a molecule of alkene.

The general formula of alkynes is [tex]C_n H_{2n-2}[/tex] where n is the number of the carbon atoms present in a molecule of alkyne.

(a) An alkane with 22 carbon atoms

Putting n = 22 in the general formula of alkane, we get the formula of alkane as, [tex]C_{22}H_{2(22)+2}[/tex] or [tex]C_{22}H_{46}[/tex]

(b) An alkene with 17 carbon atoms

Putting n = 17 in the general formula of alkene, we get the formula of alkene as, [tex]C_{17}H_{2(17)}[/tex] or [tex]C_{17}H_{34}[/tex]

(c) An alkyne with 13 carbon atoms

Putting n = 13 in the general formula of alkyne, we get the formula of alkyne as, [tex]C_{13}H_{2(13)-2}[/tex] or [tex]C_{13}H_{24}[/tex]

Answer:

[tex]\huge \boxed{{C_{22} H_{46} \ \ \ \ C_{17} H_{34} \ \ \ \ C_{13} H_{24}}}[/tex]

Explanation:

[tex]alkanes \ \Rightarrow \ C_n H_{2n+2}[/tex]

[tex]C_{22} H_{2(22)+2}[/tex]

[tex]C_{22} H_{44+2}[/tex]

[tex]C_{22} H_{46}[/tex]

[tex]alkenes \ \Rightarrow \ C_n H_{2n}[/tex]

[tex]C_{17} H_{2(17)}[/tex]

[tex]C_{17} H_{34}[/tex]

[tex]alkynes \ \Rightarrow \ C_n H_{2n-2}[/tex]

[tex]C_{13} H_{2(13)-2}[/tex]

[tex]C_{13} H_{26-2}[/tex]

[tex]C_{13} H_{24}[/tex]

Answer:

a. N₂(g) + O₂(g) → 2 NO(g)

b. 2 HgO(s) → 2 Hg(l) + O₂(g)

c. 4 Fe(s) + 3 O₂(g) → 2 Fe₂O₃(s)

d. 2 Na(s) + Cl2(g) → 2 NaCl(s)

e. 2 Cu₂O(s) + O₂(g)  → 4 CuO(s)

Hope this helps.

Answer: B: Earths tilt

Explanation:

Seasonal variation occurs because the Earth is tilted on its axis by 23.5˚. As Earth orbits the sun, its orientation to the sun changes.

Answer:

E. Mass number

H. Ion

F. Isotopes

I hope you have a great day. I'm sorry that I didn't know C or I.

Answer:

N for chlorate ion is one

Explanation:

Because N is the number of electrons needed to form octet structure causing a negative charge of one, since it already has 25valence electrons

Answer: 26

Correct Answer

Answer:

No because hydrogen chloride is gas and hydrochloric acid is (as stated in the name) an acid. The formula for hydrogen chloride is HCI(g), the little g states that the compound is a gas and the formula for hydrochloric acid is HCl(aq) and the little aq means aqueous.

Answer:

no. they are not the same

Explanation: Although, they both do have the same chemical formula HCL, they differ in their states of matter. Hydrogen chloride is a gas whereas hydrochloric acid is a solution of hydrogen chloride gas and water( creates an aquaeous solution). Hydrochloric acid is highly corrossive.

Answer:

C. They have the same number of protons.

Explanation:

Even though in isotopes, there's uneven number of neutrons, there's always same number of protons.

Hope it helps.

Answer:

Yes

Explanation:

What's the question?

Answer:

yes, they both use it to fllight.

Explanation:

As they are adapted to flight to various places to catch their prey and be safe from various type of harms.

hope it helps..

Answer:

Jeweler B = more accurate

Jeweler A = more precise

Error:

0.008, 0

% error :

0.934% ; 0

Explanation:

Given that:

True mass of nugget = 0.856

Jeweler A: 0.863 g, 0.869 g, 0.859 g

Jeweler B: 0.875 g, 0.834 g, 0.858 g

Official measurement (A) = 0.863 + 0.869 + 0.859 = 2.591 / 3 = 0.864

Official measurement (B) = 0.875 + 0.834 + 0.858 = 2.567 / 3 = 0.8556

Accuracy = closeness of a measurement to the true value

Accuracy = true value - official measurement

Jeweler A's accuracy :

0.856 - 0.864 = - 0.008

Jeweler B's accuracy :

0.856 - 0.856 = 0.00

Therefore, Jeweler B's official measurement is more accurate as it is more close to the true value of the gold nugget.

However, Jeweler A's official measurement is more precise as each Jeweler A's measurement are closer to one another than Jeweler B's measurement which are more spread out.

Error:

Jeweler A's error :

0.864 - 0.856 = 0.008

% error =( error / true value) × 100

% error = (0.008/0.856) × 100% = 0.934%

Jeweler B's error :

0.856 - 0.856 = 0 ( since the official measurement as been rounded to match the decimal representation of the true value)

% error = 0%

Answer:

Expanding earth and contracting earth

Explanation:

Answer:

A and C

Explanation:

Answer:

A.floodplains and alluvial fans .

Explanation:

Hope it helps.

Answer:A)

Explanation:

Answer: Compound

Explanation:  pure substance that cannot be broken down into simpler substances by chemical or physical means. Each element has unique physical and chemical properties.

Answer:

The answer is option C.

Hope this helps you

Answer:

5

Explanation:

Distilled water has a pH of 7 while CO2 is slightly acidic and therefore if we combine both substances we should get a pH just below 7 which if 5

Answer:

A) 5

Explanation:

5

The pH of distilled water immediately after distillation is 7, but within hours after distillation, it has absorbed carbon dioxide from the atmosphere and become acidic with a pH of 5

Answer:

FROM the magnetic point of view, phosphorus is an extremely interesting

substance because of its allotropic modifications. The ordinary forms are

the yellow (or white) and the red varieties. X-ray investigations indicate

that probably yellow phosphorus is analogous with the cubic forms of antimony and arsenic; and red phosphorus with monoclinic antimony and

arsenic (Mellor, 1928). The conclusions of different workers on the structure of red phosphorus are not in agreement. There is also Bridgman's black

phosphorus which is probably hexagonal (Linck and lung, 1925). Natta

and Passerini (1930) have studied the crystal structure of white phosphorus.

This substance when condensed at the temperature of liquid ammonia is

cubic. Atomic positions however are yet undetermined. Another and noncubic form is obtained by condensation at liquid-air temperatures. It is

thus clear that most likely white phosphorus is cubic in structure with a

probable superposition of another lattice.

The evidence from Raman effect also points to the same conclusion.

Bhagavantam (1930) investigated the Raman effect of white phosphorus in

the solid state. The characteristic frequencies obtained by him are 607, 468

and 374. Since the phosphorus molecule is known to contain 4 atoms,

Bhagavantam (1930) has shown that the tetrahedral structure fits the results

satisfactorily since such a structure would give only three frequencies. But

for the particular law of forces adopted, the frequencies should have the

ratio 2: 2: 1 but the observed frequencies deviate considerably.

Phosphorus is a really intriguing element. because of the allotropic changes to the material.

Red phosphorus is likely akin to monoclinic antimony, while yellow phosphorus is probably similar to the cubic forms of antimony and arsenic.

There is disagreement among the findings of many researchers regarding the structure of red phosphorus. Additionally, Bridgman's black It is presumably hexagonal, phosphorous (Linck and lung, 1925). Natta and Passerini (1930) have investigated the white phosphorus crystal structure.

Condensed from this material at liquid ammonia temperature is cubic. However, the locations of the atoms are still unknown. Condensation at liquid air temperatures yields a different, noncubic shape.

Therefore, Phosphorus is a really intriguing element. because of the allotropic changes to the material.

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Answer:

atoms are bonded with a single bond one double bond

Answer:

Option D. For every mole of iron oxide consumed, two moles of iron are produced.

Explanation:

The balanced equation for the reaction is given below:

Fe2O3 + 3CO —> 2Fe + 3CO2

From the balanced equation above,

1 mole of iron oxide, Fe2O3 reacted with 3 moles of carbon monoxide, CO to produce 2 moles of iron, Fe and 3 moles of carbon dioxide, CO2.

Thus, with a careful observation of the equation, we can conclude that for every 1 mole of iron oxide, Fe2O3 consumed, 2 moles of iron, Fe are produced.