Since the beginning of time, some people have believed that the Earth is flat. Beginning around 300 B.C., however, some began to wonder if the Earth is actually spherical in shape. Those that favored the flat Earth theory made the following observations: The Earth is stable because it is a flat landmass sandwiched between a flat layer of air and a flat layer of water. If the Earth is spherical, then oceans should be curved on top, but they aren't. Some rivers flow for hundreds of miles but only fall a few feet. The rivers should fall farther if the Earth is spherical. If the Earth is spherical, people and animals that inhabit the Earth would notice as they walked along its surface. Since mariners are able to use flat compasses to navigate their ships without crashing, the Earth must not be a sphere. Those that disputed the flat Earth theory countered the claim by observing that Christopher Columbus was able to sail around the Earth without falling off the edge and later, by presenting satellite imagery taken from space of a spherical Earth. This example demonstrates that

The pH of the solution is 1.12.

HNO₃ is a strong acid, which means it completely dissociates in water to form H⁺ and NO₃- ions.

The number of moles of HNO₃ added is 1.0 mole.

The final volume of the solution is 1.5 L, so the concentration of HNO₃ can be calculated as:

[HNO₃] = number of moles / volume (in liters) = 1.0 mole / 1.5 L = 0.67 M

Since HNO₃ is a strong acid, it completely dissociates to form H+ ions. Therefore, the concentration of H⁺ ions is equal to the concentration of HNO₃:

[H⁺] = [HNO₃] = 0.67 M

Now, we can calculate the pH using the following equation:

pH = -log[H⁺] = -log(0.67) = 1.12

Therefore, the pH of the solution is 1.12.

Calcium and lithium are oxidized and Florine and oxygen are reduced.

Oxidizing agent are defined as a substance or component that participates in an oxidation-reduction reaction and receives electrons from a separate species. The oxidizing agent, often referred to as the electron acceptor, is typically in one of its higher oxidation states since it will receive electrons and be reduced.

Reducing agent are defined as a reactant in an oxidation-reduction reaction that decreases another reactant by discharging electrons to that reactant. Reducing one's consumption of energy-dense foods and canceling undesired magazine subscriptions are two examples. Another example of reduction is to turn off the water when brushing your teeth rather than letting it run the full two minutes.

Thus, calcium and lithium are oxidized and Florine and oxygen are reduced.

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Final answer:

Niobium has five unpaired electrons, with one electron from the 5s orbital and four electrons from the 4d orbitals, following Hund's rule.

Explanation:

The student asked about the number of unpaired electrons in niobium. Niobium (Nb) has the atomic number 41, which means its electron configuration is [Kr]4d45s1. In the niobium atom, there are five electrons in its outermost d and s orbitals, out of which one can be found in the 5s orbital and four in the 4d orbitals. According to Hund's rule, which states that every orbital in a subshell is singly occupied before any orbital is doubly occupied and all electrons in singly occupied orbitals have the same spin, we can expect at least one unpaired electron in niobium due to its electron configuration.

To determine the exact number of unpaired electrons, we need to look more closely: the single electron in the 5s orbital is unpaired, and within the 4d subshell, which can hold up to 10 electrons, there are four electrons. These will occupy the first four orbitals singly before pairing up, resulting in four unpaired electrons from the 4d subshell. Therefore, niobium has a total of five unpaired electrons, one from the 5s orbital and four from the 4d orbitals.

The ball stops moving because of friction force. Friction is the force that opposes all motion. Therefore, the answer is friction force...

Answer:

friction

Explanation:

took test

Answer:

Fragmentation

Explanation:

APEX

Considering the definition of the Law of Conservation of Matter, the correct answer is option D. Atoms of each element are conserved, so the total mass does not change.

The Law of Conservation of Matter is also called the law of conservation of mass or the Law of Lomonósov-Lavoisier. This law postulates that "the mass is not created or destroyed, only transformed."  

This means that the reagents interact with each other and form new products with physical and chemical properties different from those of the reagents because the atoms of the substances are ordered differently. But the amount of matter or mass before and after a transformation (chemical reaction) is always the same, that is, the quantities of the masses involved in a given reaction must be constant at all times, not changing in their proportions when the reaction ends.  

In other words, then the mass before the chemical reaction is equal to the mass after the reaction. The exception to the rule is nuclear reactions, in which it is possible to convert mass into energy and vice versa.

Taking into account the above, the correct answer is option D. Atoms of each element are conserved, so the total mass does not change.

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You have this in Chemistry. It should be in physics, but never mind that.

A

d = 4 km due east. See note for part B.

t =  45 minutes = 3/4 hour

v = ??

d = v * t

4 = v * (3/4)

v = 4/(3/4) = 4 * 4/3 = 16/3 = 5 1/3

So his rate of travel is 5 1/3 km/hr due east. If you do not give the direction when it says velocity, you are wrong. Velocity has direction.

B

10 45 to 11 45 is 1 hour.

d = v * t

d = 6 km due south (this is actually a displacement which also has direction). 

t = 1 hour

6 = v * (1)

6/(1) = v

6/(1) = v

v = 1 km/ hr due south 

Answer:gold

Explanation:

yeah weight is the answer

Using the balanced chemical equation 2C + Cu2O → 2CO + 2Cu, it can be determined that 1.98 moles of carbon will produce 1.98 moles of carbon monoxide (CO) when reacting with an excess of copper(I) oxide.

The subject of this question is Chemistry, specifically dealing with stoichiometry which involves the calculation of the amounts of reactants and products in chemical reactions. Given that 1.98 moles of carbon (C) react with an excess of copper(I) oxide (Cu2O), we need to know the balanced chemical equation to find the amount of carbon monoxide (CO) produced.

The chemical equation for the reaction between carbon and copper(I) oxide to produce carbon monoxide and copper would be:

2C + Cu2O → 2CO + 2Cu

From this balanced equation, we can see that 2 moles of carbon react with 1 mole of copper(I) oxide to produce 2 moles of carbon monoxide. Therefore, if we start with 1.98 moles of carbon, we will also produce 1.98 moles of CO, since the ratio of carbon to carbon monoxide is 1:1.

When 1.98 moles of C are reacted with an excess of Cu2O, it would produce 1.98 moles of CO assuming the reaction follows the stoichiometry of 2 moles of C producing 2 moles of CO.

If 1.98 moles of C are reacted with an excess of Cu2O, the number of moles of CO produced can be determined by using stoichiometry and the balanced chemical equation for the reaction. Unfortunately, the actual balanced chemical equation is not provided in the question. However, a typical reaction between carbon and copper (I) oxide might look like this:

2C(s) + Cu2O(s) → 2CO(g) + Cu(s)

According to this balanced equation, 2 moles of carbon react with 1 mole of copper(I) oxide to produce 2 moles of carbon monoxide. Therefore, if we have 1.98 moles of carbon, it would produce 1.98 moles of CO, assuming carbon is the limiting reactant and since there's an excess of Cu2O.

Answer: Option (B) is the correct answer.

Explanation:

In a solid object, molecules are closely packed together due to strong intermolecular forces between them. So, when heat is provided to the object then forces between the atoms decreases and as a result, atoms start to move from their initial place.

Hence, atoms gain kinetic energy due to increase in their motion.

For example, when ice is heated it changes into liquid state of water.

Also, K.E = [tex]\frac{3}{2}kT[/tex]

where     k = Boltzmann constant

              T = temperature

Hence, kinetic energy is directly proportional to temperature.

Thus, we can conclude that the temperature of an object is directly related to the motion of its particles.

Factors that determine sound intensity are amplitude and the distance.

Amplitude 
Amplitude depends on the starting energy of the sound wave. If the amplitude is high then the intensity will be high.

Distance
Distance is the measure of how far does the sound wave travel from its source. If the distance is high then the intensity will be low.

Answer: Option (A) is the correct answer.

Explanation:

When we place two objects of different temperature adjacent to each other then there will occur transfer of heat from hotter object to colder object till their temperature becomes equal.  

This process is known as conduction.

For example, a metal spoon placed in hot coffee cup then heat will flow from coffee to the cup.

Convection is defined as the process in which a fluid (liquid or gas) when heated then more dense (cooler) substance sinks ate the bottom whereas less dense (hotter) substance will rises at the top.  

This intermixing of the substances tends to generate convection currents and this process is known as convection.

Radiation is defined as an electromagnetic energy which travels in space in the form of waves or particles.

This means that heat energy will always travel from a warmer object to a colder object.

Thus, we can conclude that heat ALWAYS flows from warmer objects to cooler objects, is a true statement about heat transfer through conduction, convection, or radiation.

The statement 'heat ALWAYS flows from warmer objects to cooler objects' is TRUE about heat transfer through conduction, convection, or radiation (Option A).

In conclusion, the statement 'heat ALWAYS flows from warmer objects to cooler objects' is TRUE about heat transfer through conduction, convection, or radiation (Option A).

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Answer:

remains constant