Which part of the atom has to stay the same for it to be the same element? a) number of neutrons b) number of protons c) number of electrons d) number of protons, neutrons, and electrons

Answer:

to increase surface area or A

Explanation:

The density of the object can be calculated using the formula Density = Mass / Volume. With the given mass of 40g and an volume of 31 cm³, the calculated density is 1.29 g/cm³.

The essential formula to remember here is: Density = Mass / Volume (represented as p=m/v), which you can use to calculate the density of any object if you know its mass and volume.

In this scenario, the mass (m) is given as 40g and the volume (V) as 31 cm³. Substituting m and V into the density formula gives:

Density = 40g / 31 cm³ = 1.29 g/cm³

Therefore, the density of the object in question is 1.29 g/cm³.

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1) Answer is: False.

A period in the periodic table is a horizontal row. For example, sodium and chlorine are in third period and they have very different properties. Sodium is solid metal and chlorine is gaseous nonmetal. Elements in the same row have the same number of electron shells, but different proporties.

2) Answer is: True.

Group is a column of elements in the periodic table. For example, lithium and sodium are in 1 group of the periodic table and they both have one valence electron.

3) Answer is: valence electrons.

For example, electron configuration of oxygen atom: ₈O 1s² 2s² 2p⁴.

Oxygen atom has six valence electrons, so it is in 16 group of Periodic table of elements.

Answer:

The answer is B. Place a 2 in front of the HCl

Ba + 2HCl → BaCl2 + H2

Explanation:

According to the law of the conservation of matter, no atom can create or destroy in a chemical reaction. Then the number of atoms that are present in the reagents has to be equal to the number of atoms present in the products. Therefore, if the number of atoms is not equal, the equation must be balanced.

First you must determine the amount of atoms of each element present in both reagents and products. For that you must observe the subscripts next to each atom. In this case:

Reagents (left side of the reaction):

Products (right side of the equation):

You can see that there aren't the same number of atoms of Cl and H in reagents and products. So you have to balance the chemical reaction.

In a chemical equation, you can change coefficients, but you should never alter the subscripts. And it is always preferable not to start balancing with H. In this case, you start balancing the chlorine. For that you add the coefficient 2 to the HCl molecule to the right of the equation to balance it with the 2 Cl atoms to the left of the equation (present in BaCl2). So:

Ba + 2HCl → BaCl2 + H2

Now you must determine the amount of atoms of each element present in both reagents and products again to see if the reaction is balanced or not. Remember that by multiplying the coefficient by the subindice of each atom, you get the amount of that atom.

Reagents (left side of the reaction):

Products (right side of the equation):

You can see that you have the same amount of each atom on each side of the reaction. This means that the reaction is balanced.

So the answer is

Ba + 2HCl → BaCl2 + H2

and you placed a 2 in front of the HCL

Final answer:

The distance vs. age plot is expected to show a positive correlation if the Pacific Plate is moving over a stationary hotspot, with older volcanoes/mountains being farther from Kilauea. A lack of pattern, like in the Line Islands, suggests a complex tectonic history. Correlation analysis and topographic and tectonic interpretations are pivotal in examining volcanic activity and age-distance relationships.

Explanation:

The relationship between the age of volcanoes/mountains and their distance from Kilauea can be determined by analyzing a distance vs. age plot. As the distance from Kilauea increases, we generally expect the age of the volcanoes/mountains to increase as well, if the hypothesis that the Pacific Plate is moving over a stationary hotspot is correct. A positive correlation between distance and age would support this, suggesting that the older features are farther away from the current hotspot location because they were formed first and have been carried away by the plate motion over time.

Conversely, if there is no clear pattern or relationship between age and distance, it could indicate a more complex tectonic history, as suggested by the Line Islands, which do not show a clear age-distance relationship. This lack of pattern could be due to different tectonic movements or the presence of multiple hotspots, as opposed to a single, stationary hotspot. The concept of correlation, which can be positive or negative, is crucial in interpreting such geologic data. As demonstrated in the example with Old Faithful's eruptions, where there's a positive correlation between eruption duration and the time between eruptions, we can use similar methods to determine the age-distance relationship.

Critical thinking about the topography and tectonic history can provide insights into why one area might have larger volcanic eruptions compared to another. Factors such as rift zones, plate boundaries, and hotspots might influence the eruption style and magnitude.

The AWNSER i think is c and do you use time4learning

The electrons in the outermost shell, or energy level, of an atom are Valence electrons. Electron dot model is a model that shows only the valence electrons of an atom, i.e., option C.

Because valence electrons are so crucial, atoms are frequently represented by simple diagrams that only show their valence electrons.

These are known as electron dot diagrams. Also referred to as Lewis structures.

Electron dot model is a model that shows only the valence electrons of an atom.

Thusm the correct option is C.

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Final answer:

The wind blowing a sand dune exemplifies sediment deposition by wind, commonly observed in deserts and coastal areas, and involves processes that create well-sorted, often red colored sands. This phenomenon is also significant in planetary science, evidenced by features on Mars reshaped by wind, such as large dune fields and yardangs aligned with the wind direction.

Explanation:

The wind blowing a sand dune is an example of sediment deposited by wind, which is a process often observed in deserts and coastal regions. Sand dunes formed by wind deposition are typically composed of well-sorted sand, which can be red in color due to the oxidation of iron-bearing minerals. This type of sediment transport is due to the variable energy of the wind, which can range from gentle breezes capable of slowly shifting grains of sand to powerful gusts that rapidly reconfigure the dune landscape.

Studying the effects of wind on sand dunes is not only relevant to Earth but also to planetary science, as seen with the exploration of surface features on Mars. Here, wind plays a pivotal role in reshaping the landscape, creating features such as large dune fields, intricate patterns caused by dust devils, and exposing underlying darker materials that give rise to contrast in coloration on the Martian surface. The dynamic nature of wind erosion and deposition is evident in the existence of yardangs, ridges that are aligned with the dominant wind direction and carved by persistent, strong winds.

In summary, the movement of a sand dune by wind is a clear illustration of the power of natural forces to shape and alter landscapes on Earth and other celestial bodies like Mars, particularly in areas characterized by a scarcity of water and vegetation that might otherwise anchor the surface material.

Answer:

I think it is da C

Explanation:

Later ✌️

What is the group number of the most nonmetallic group that contains metalloids?

16

What is the group number of the most metallic group that contains metalloids?

13

Explanation:

Metalloids are the substances which show properties of both metals and non-metals.

The left side of periodic table contains metals and on moving towards the right there are non-metals. Between the metals and non-metals there are metalloids.

Group 16 is the most non-metallic group that contains metalloids. In group 16, O, S, and Se are non-metals whereas Te and Po are metalloids.

Group 13 is the most metallic group that contains metalloids. In group 13, Al, Ga, In and Tl are all metals whereas boron is a metalloid.

Answer: [tex]C_5H_{12}+8O_2\rightarrow 5CO_2+6H_2O]/tex]

Explanation:

According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.

Combustion is a type of chemical reaction in which fuel is reacted with oxygen to form carbon dioxide and water.

[tex]C_5H_{12}+O_2\rightarrow CO_2+H_2O]/tex]

The balanced equation will be :

[tex]C_5H_{12}+8O_2\rightarrow 5CO_2+6H_2O]/tex]

Usually the uncertainty of a graduated cylinder is given however if it is not, then it is simply assumed to be equal to half of the least interval of that instrument. In this case, the least interval is 10 ml, so half of this is 5 ml. Hence, the graduated cylinder has an uncertainty of +/- 5 ml

Challenging a scientific theory is an essential part of the scientific process, not an indication of a theory's weakness. Theories are meant to be falsifiable and robust, able to withstand scrutiny and adapt to new evidence. Criticism and challenge signify the self-correcting nature of science.

The statement "Any time a scientific theory is challenged, it means it's not a good theory" is a misconception about the nature of scientific inquiry. In science, challenging theories is fundamental to scientific progress.

When a theory is challenged, it does not necessarily mean the theory is weak or incorrect; rather, it's an opportunity to test the robustness of the theory. Scientific theories are built to be falsifiable, meaning that they can be tested against observations and experiments. If a theory cannot be falsified, it's not considered a strong scientific theory.

When we encounter data that contradicts a theory, it's critical to examine this data critically. Sometimes, after scrutiny, the data may not be credible, but other times it can lead to a theory being revised or replaced. A revolutionary scientific theory is often not accepted until it has undergone rigorous testing and scrutiny, potentially replacing an older theory. Valid criticism and challenges to a theory, rather than indicating poor quality, demonstrate the self-correcting nature of the scientific method.

Moreover, the progress of science involves improving upon or discarding theories when new evidence arises. In this sense, science has no sacred ideas that cannot be challenged.

The strength of a scientific model lies in its ability to withstand challenges and adapt to new data. If a theory does not fit within the observed data or if new information arises that contradicts the theory, it is the standard scientific practice to either modify the theory or develop a new one that better explains the phenomena.

Answer:  114.29 mL

Explanation:

We are given that density of ether = 0.70 g/ml

Mass of ether= 80.0 g

Formula to calculate the density is given by :-

[tex]\text{Density}=\dfrac{\text{Mass}}{\text{Volume}}[/tex]

Substitute the value of density and mass , we get

[tex]0.70=\dfrac{80.0}{\text{Volume}}\\\\\Rightarrow\text{Volume}=\dfrac{80}{0.70}=114.285714286\approx114.29\ mL[/tex]  [Rounded to the nearest two decimal places.]

Hence, the volume of ether = 114.29 mL

Construct a hypothesis  part of the scientific method is he missing from this scientific investigation. Thus option B is correct.

Scientific investigation is a continuous process involving different steps to find out the answer to a real question by using method and experimental data.

The basic steps include to make observation from different sources, to develop, experiment and improve a hypothesis and formulate the explanation based on an observed phenomenon.

The different steps of Scientific Investigation are making Observation in scientific investigation is the first step to observe the process involve in the step of inspection, conducting the investigations.

Asking Questions another step used based on observation to make sure that every detail is known and a query can be solved quickly, Formulation of a Hypothesis involves explanation of  the query which is most significant part of the scientific investigation.

conclusion leads to  drawn out of the information which should be proper scientific or a mathematical statement followed by Communication of the information from the investigation

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A balanced chemical equation should have same number of same kind of atoms with the same charge on both the sides of reaction.

In other words, a chemical reaction where the number of atoms for each element in the reaction and the total charge on them are the same, for both the reactants and the products is called as a balanced chemical equation.

Also, the mass and the charge should balanced on both sides of the reaction.

Final answer:

The best description of a balanced chemical equation is that it has the same number of the same kind of atoms on both sides, reflecting the conservation of matter. Balancing involves adjusting coefficients to achieve this equality.

Explanation:

The statement that best describes a balanced chemical equation is 'D. There are the same number of the same kind of atoms on either side of the reaction.' Balancing a chemical equation ensures compliance with the law of conservation of matter, indicating that atoms are neither created nor destroyed in a chemical reaction.

To balance a chemical equation, we insert coefficients in front of the appropriate reactants or products until there is the same number and type of atoms on both sides of the arrow. For instance, if a reaction produces CO₂ and H₂O, we would count the oxygen atoms in both molecules to ensure they match the total number of oxygen atoms in the reactants.

Therefore, balancing equations is a fundamental process in chemistry that illustrates the conservation of atoms during chemical reactions and ensures that the numbers of each type of atom are equal on both sides of the equation.

A pure substance contains its own contents only. The pure substance among the given options is pumpkin pie because it contains no other contents.

What is a pure substance?

A pure substance contains only its own contains and not any other things are added to it. Water Itself is pure despite the quality of water. But when we add salt or sugar to it it cannot be classified as a pure substance.

Salt is a naturally made chemical compound but it might contains some impurities and the traces other minerals in it since it is collected from the sea.

Iced tea is not classified as pure because, it contains ice, tea powder, sugar and water. Thus, it is a mixture of different substances. Pumpkin pie is naturally made fruit  contains its pulp and seed only not any added things are there.

Hence, pumpkin pie can be classified as a pure substance and option C is correct.

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Final answer:

Gases are not a part of every chemical reaction, unlike reactants, products, and energy changes which are essential components of all reactions.

Explanation:

What is not part of every chemical reaction? The answer is C. gases. While every chemical reaction involves reactants and products, and energy changes (either absorption or release), not all chemical reactions produce or involve gases. Reactants are the substances present at the beginning of a reaction, and products are the substances formed as a result of the reaction. Energy is a fundamental component of chemical reactions, as it is either released or absorbed during the process. In contrast, the production of gases is specific to certain types of reactions and is not a universal aspect of all chemical reactions.

In every chemical reaction, energy is not always a part of the reactants or products involved. While reactants and products are essential components of a chemical reaction, gases and energy are not universally present in every reaction.

Answer:

Suppose you were to make a ring from a single strand of gold atoms. Then you have to take the following steps;

Let us assume that the ring is a size 7 ring, which has a circumference of 54.3 millimeters. Converting this to centimeters, the circumference of the ring is:

54.3 mm = 5.43 cm

Now, we determine the number of gold atoms that will be present in this:

5.43 / 1 x 10⁻⁹

There will be 5.43 x 10⁹ atoms

We now determine the number of moles this is by:

one mole = 6.02 x 10²³ atoms

Moles = 5.43 x 10⁹ / 6.02 x 10²³ 

Moles = 9.01 x 10⁻¹⁵ moles

The molar mass of gold is 197 g/mol

The mass is 9.01 x 10⁻¹⁵  * 197

The mass of the strand is 1.76 x 10⁻¹² grams