Given the balanced equation:4Fe(s) + 3O2(g) ==>2Fe2O3(s) + 1640 kJ
Which phrase best describes this reaction?
(1) endothermic with DH = +1640 kJ
(2) endothermic with DH = -1640 kJ
(3) exothermic with DH = +1640 kJ
(4) exothermic with DH = -1640 kJ

Answers

Answer 1
Answer: The answer is (4) exothermic with ΔH = -1640 kJ. The 1640 kJ energy is at the right side of equation means that it releases energy. The enthalpy change means the energy of production minus the energy of reactants. If it is exothermic, the ΔH < 0.

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Mixtures can be either_____
(fixed composition) or_____
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Answers

Mixtures can be either fixed composition or variable composition.

A fixed composition mixture is a mixture that has a constant and unchanging composition, meaning that the proportions of the components remain the same throughout the mixture. Examples of fixed-composition mixtures include solutions, suspensions, and colloids. In a solution, for example, the solute is dissolved in the solvent in a specific ratio, and the composition of the solution remains constant. In a suspension, the particles of one substance are suspended in another substance, but the composition of the suspension remains constant. In a colloid, the particles of one substance are dispersed throughout another substance, but the composition of the colloid remains constant.

On the other hand, a variable composition mixture is a mixture that can change its composition over time. Examples of variable composition mixtures include gases and solutions that are not in equilibrium. In a gas, the molecules are free to move and interact with each other, so the composition of the gas can change over time. In a solution that is not in equilibrium, the components can separate or mix over time, leading to changes in the composition of the solution.

It's important to note that the composition of a mixture can be influenced by a variety of factors, including temperature, pressure, and the presence of other substances. For example, the composition of a solution can be affected by changes in temperature, as the solute and solvent can interact differently at different temperatures. Similarly, the composition of a gas can be affected by changes in pressure, as the molecules can move more or less freely at different pressures.

In conclusion, mixtures can be either fixed composition or variable composition, and the composition of a mixture can be influenced by a variety of factors. It's important to understand the composition of a mixture in order to understand its properties and behavior.

This is an interaction in which two waves meet, matching crest to crest and trough to trough. The resultant wave will have an amplitude of the sum of the two.

Answers

I'm Osei George the answer is interference

Answer:deferehug

Explanation:

Over 100 existing elements are listed and classified on the ____________________.

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Final answer:

The Periodic Table of Elements lists over 100 known elements, providing critical information such as the element's atomic number, symbol, name, and atomic mass. Elements are grouped based on their chemical properties and electron configuration.

Explanation:

Over 100 existing elements are systematically organized and displayed on the Periodic Table of Elements. Each box on the Periodic Table represents a different element and provides critical information such as the element's atomic number, symbol, name, and atomic mass. Elements are grouped together based on their chemical properties and electron configuration, which is a representation of the organization of electrons around the nucleus.

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Final answer:

Over a hundred elements, both naturally occurring and experimentally discovered, are listed and classified on the Periodic Table of the Elements. They are sorted by atomic number, and those with similar properties and valence shells are grouped into columns and rows respectively.

Explanation:

Over 100 existing elements are listed and classified on the Periodic Table of the Elements. This list of elements is arranged in ascending order of atomic number, which is the number of protons in each nucleus. The periodic table not only identifies the chemical symbol, atomic number, and mass number of each element but also groups elements according to their propensity to react with other elements.

It's important to note that elements found on the periodic table have an equal number of protons and electrons. However, the number of protons and neutrons may not always be equal across all elements. In addition to the 92 naturally occurring elements, there are several larger, unstable elements that have been discovered experimentally

Aside from organizing elements according to their atomic number, the periodic table is also structured in a way that elements with similar properties compose columns in the table, while elements with the same number of valence shells compose rows, making it an essential tool for understanding and predicting chemical behaviors.

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Other planets have an atmosphere, but Earth's is unique because it has large amounts of _____.nitrogen
oxygen
water vapor

Answers

the answer is oxygen because, all the other planets don't provide life and air

Just had this question, oxygen is the correct answer

HELPPPP I WILL GIVE YOU BRAIN THINGG WHATEVER ITS CALLED We have learned that there are five steps to reading a new piece of music. Can you name all five steps?

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Notes, Pitches, Articulation, Phrasing, and Musical Extras.

Why is tin foil a good insulator

Answers

Tin foil is a heat insulator because it can reflect radiation. When tin foil, for instance, is wrapped around an object, air can be trapped. Trapped air is a good insulator against convection.