Answer:
The nuclear charge increases, but the number of inner shielding electrons stays the same.
Explanation:
Their shielding does not change, so the effective nuclear charge — the charge felt by a valence electron — increases.
The valence electrons are pulled closer to the nucleus, decreasing the atomic radius.
For example, consider the elements of Period 3.
The number of protons increases as you go from one element to the next, but the number of inner electrons is constant.
A 'spontaneous reaction' in chemistry refers to a reaction that continues on its own once started, not a reaction that starts spontaneously. A sparkler, once lit, undergoes a combustion reaction that needs no additional energy input.
The term spontaneous reaction in chemistry does not mean that a reaction starts spontaneously without any trigger. It actually refers to a reaction that, once started, continues without any additional external input. In the case of a sparkler, the initial energy to start the reaction is provided by lighting the sparkler. Once lit, the combustion reaction continues on its own, making it a spontaneous reaction.
The reactants in the sparkler (often metal powders and an oxidizing agent) are in a higher energy state than the products (typically metal oxides and heat) they form during burning. This difference in energy drives the reaction forward, making it spontaneous. The overall energy of the system decreases, which aligns with the principle of thermodynamics stating that a spontaneous process leads to a decrease in the system's free energy.
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A. Elements cannot be broken down into simpler substances.
B. Elements are represented by chemical formulas.
C. Elements are pure substances.
D.Elements can combine chemically to form compounds.
Answer:
It is B.
All the other answers are true.
A element can not be simpler
The correct answer is B. Elements are represented by chemical formulas.
Out of the given options, the correct answer is B. Elements are represented by chemical formulas.
Chemical formulas are used to represent compounds, not elements. Elements are pure substances that are made up of only one type of atom and cannot be broken down into simpler substances. They are represented by their chemical symbols, such as H for hydrogen and O for oxygen.
For example, water is a compound made up of two elements: hydrogen and oxygen. The chemical formula for water is H2O, where H represents hydrogen and O represents oxygen.
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Do high pressure systems prefer forming in Ecuador compared to in Springdale?
Are thunderstorms in Ecuador as scary as thunderstorms in Springdale?
Are average yearly temperatures in Ecuador greater than in Springdale?
The only testable question from the options provided would be asking if the average yearly temperatures in Ecuador are greater than those in Springdale. This question allows for a factual comparison using data.
When comparing climates, we must focus on quantitative, measurable aspects. So, the testable question here most appropriate for Sam's inquiry would be: Are average yearly temperatures in Ecuador greater than in Springdale?. This question relies on measurable, empirical data related to the large scale weather patterns of two distinct geographic locations. It will allow a factual analysis of the differences in climate between Springdale and Ecuador, specifically in terms of average yearly temperatures.
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» A change in
means that a chemical reaction has occurred.
Answer:
C) the properties and identity of the reacting substances
Explanation:
took the test
Answer:
.....
Explanation:
Chemical changes occur when bonds between atoms are broken and new bonds form. As a result, new substances are produced. There are four signs that a chemical reaction has occurred: a change in color, a change in temperature, formation of a gas or formation of a precipitate.