Answer:
For 1: The chemical species present at the start of the chemical reaction are reactants.
For 2: Hydrogen gas and oxygen gas synthesizing into liquid water is a chemical reaction.
Explanation:
For 1:In a chemical equation, the chemical species are termed as reactants or products.
Reactants are defined as the species which react in the reaction and are written on the left side of the reaction arrow. They are present at the start of the reaction.
Products are defined as the species which are produced in the reaction and are written on the right side of the reaction arrow. They are present at the end of the reaction.
[tex]\text{Reactants}\rightarrow \text{Products}[/tex]
Hence, the chemical species present at the start of the chemical reaction are reactants.
For 2:Physical change is defined as the change in which change in shape and size takes place. The chemical composition of a substance remains the same. No new substance is formed during this.
Chemical change is defined as the change in which change in chemical composition takes place. A new substance is formed in this.
For the given options:
Option A: A solid chocolate is melting into liquid chocolate by providing heat. The shape of the chocolate is changing. So, its a physical change.
Option B: When a peanut shell is cracked up, the size of the peanut shell is changed. So, it is a physical change.
Option C: When water vapor is cooled down to form liquid water, no new substance is getting formed. So, it is a physical change.
Option D: When hydrogen gas reacts with oxygen gas, it leads to the formation of water. As, new substance is getting formed. So, it is a chemical change.
[tex]2H_2+O_2\rightarrow 2H_2O[/tex]
Hence, hydrogen gas and oxygen gas synthesizing into liquid water is a chemical reaction.
How/why does the density of an object change when heated?
What type of energy is present in the batteries of a flashlight? Mechanical energy Electrical energy Chemical energy Radiant energy
Which of the following causes clouds to form? (1 point)
A. Air cooling to its dew point
B. Water vapor condensing as it rises into cooler air
C. Air pressure rising above normal
D. Air pressure below normal
Answer:
b
Explanation:
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how does an element's period number relate to the number of the energy level of its valance electrons
The period number is the same number as the highest energy level, for the atoms on that row which is also the energy level that holds valance electrons.
What is an electron?
An electron is defined as a subatomic particle which is charged negatively either bound to an atom or not it means free. The nucleus of an atom is made up of electron, proton and neutron. The electron is a basic particle and electron is not made of anything.
The nature of electron is free it means they are present freely in nature and consist of an atom.The main function of electron is that they play the role of negatively- charged component of an atom.
The electrons are primary source of current conducting and electrons number as well as atomic number of an element is always same or equal. There is no size of electron but the mass of electron is 9×10^-31.
Therefore,the period number is the same number as the highest energy level, for the atoms on that row which is also the energy level that holds valance electrons.
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when the following two solutions are mixed: K2CO3 (aq) + Fe (NO3) 3 (aq) the
In which picture(s) will you find a state of matter that has particles who have more energy than liquid water?
This answer is B and C.
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Which of these groups includes organisms that are MOST closely related?
A) class
B) family
C) genus
D) species
Answer:
The Correct Answer is D
Explanation:
A biological species is a collection of organisms that can generate with one another in strength and create resourceful generation. The title species can also be described as the most fundamental division in the order of taxonomy.The species is the significant classification of taxonomic analysis, standing under a genus or subgenus.How many neutrons does sodium have? What is the chemical symbol for sodium? How many protons does sodium have? How many electrons does it have in the n = 2 orbit?
Final answer:
Sodium (Na) has 11 protons, 12 neutrons, and 11 electrons. It has 8 electrons in the n = 2 energy level. When it becomes a cation (Na+), it loses one electron and gains a +1 charge.
Explanation:
Sodium, with the chemical symbol Na, is an element represented in standard notation as 22Na. This notation helps us understand that sodium has 11 protons in its nucleus. The number of neutrons can be calculated by subtracting the atomic number (number of protons) from the atomic mass number, leading to the conclusion that sodium has 12 neutrons. Considering that a neutral sodium atom has an equal number of protons and electrons, it also has 11 electrons. In the n = 2 energy level, or the second shell, sodium has 8 electrons, filling the 2s and three 2p orbitals.
When sodium becomes a cation (Na+), it loses one electron, resulting in 10 electrons remaining. This cation has a +1 overall charge and is isoelectronic with neon, meaning they share the same electron configuration. A review question related to this concept asks which atom the sodium ion is isoelectronic with, and the answer is a neutral neon atom.
Is mass conserved when 50 g of sugar undergoes a physical change? Use complete sentences to support your answer by explaining how this can be demonstrated.
Answer:
1. When 50 g of sugar undergoes a physical change, say for example dissolving or melting, the amount of sugar in the solution or melted form will also be 50 grams. This shows that the mass before and after the change was the same, in accordance to the law of conservation of mass.
is true about how hydrogen and oxygen can combine to form molecules?
How many grams of water can be produced when 11.7 moles of ethane (C2H6) react with excess oxygen gas? Unbalanced equation: C2H6 + O2 → CO2 + H2O
science question down below
boiling point density conductivity color These may all be classified as the ______________ of a substance.
Boiling point density conductivity color These may all be classified as the. of a substance. - 6357722.
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what effect would over logging of trees have on the amount of carbon dioxide in the atmosphere
a scientist has 0.46 mL of a solution. How would she convert this volume to microliters?
a pure substance that contains only one atom is called a(n) _____.
A: Element
B: Compound
C: Mixture
D: Precipitate
Answer:
element
Explanation:
-compounds have two or more types of atom
-mixture can be easily separated without the use of a chemical reaction
-i dont know what a precipitate is
Answer:
element
Explanation:
Which substance would most behave as an ideal gas at STP
A. N2
B. H2O
C. CH3OH
D. HF
what is nuclear fission
what is a frame reference
Answer:
i think a measurements used when inertia is present
Explanation:
Which structure is found in a single-celled organism? A. internal organs B. legs C. outer covering D. large brain
how far below sea level is the peak of the ridge?
Final answer:
The peak's elevation below sea level is determined by its height in negative meters or feet compared to mean sea level. Historical changes, like those during the Last Glacial Maximum, have significantly affected sea levels and the geographical landscape.
Explanation:
The student's question appears to be asking about the elevation of a specific peak within a mountain ridge in relation to sea level. This likely references the concept of topographic elevation and sea level changes. To answer this question factually, we would need more specific information about the particular peak in question, including its elevation. However, generally speaking, the elevation of a point below sea level is measured as a negative number representing the distance below the standard zero point, which is the mean sea level. A notable historical fact that may help in contextual aspects of this question is that during the Last Glacial Maximum, mean sea levels were around 110 to 120 meters (361 to 394 ft) lower than they are today, meaning the coastal landscape was vastly different and what is now submerged was once dry land.
To further illustrate how elevation works, Earth's relief varies greatly from the highest point at the top of Mt. Everest to the depths of the Mariana Trench. When teaching about such elevations in a classroom setting, it's essential to understand the differences in altitude, which is the height of a point above sea level, and depth, which is the distance below sea level. Lastly, due to factors such as glacial melting and geological uplift, sea levels have changed over time. An example of this is the eustatic sea level rise of approximately 125 meters since the last deglaciation.
how do you know if a reaction is endothermic
please give a long and detailed answer i will mark brainliest and give 40 points
Compare and contrast of cotton balls and pine cone
Imagine an experiment in which hydrogen peroxide decomposes to form water and oxygen gas. hydrogen peroxide>water+oxygen gas which of the following processes could be used to show that this reaction obeys the law of conservation of matter
A. show that the mass of water produced is more than the mass of oxygen produced
B. show that the mass of water produced plus the mass of oxygen produced are together equal to the original mass of hydrogen peroxide
C. there is no way to show that the law of conservation is supported.
2. When an acid and a base react, they form new substances compare the new products with the original substances. original substance(acid+base) > new substances
A. the chemical and physical properties of the new substances are different from the properties of the original substances
B.the chemical and physical properties of the new substance are the same as the properties of the original substances
C. The chemical properties of the new substances are the same but the physical properties are different
D. the physical properties of the new substances are the same but the chemical properties are different.
In your own words, give a summary of the history of the atom. Make sure to use names of models and the scientists associated with each. Make a different paragraph for each model/scientist. (ADV is a minimum of 5 paragraphs) Notice that the Atomic Theory has changed over time as scientists have added knowledge through experimentation and use of advanced instruments. Be sure to include the following: Plum pudding model orbitals electrons gold foil experiment Bohr's model protons nuetrons nucleus
Marble statues and buildings weather more quickly today than when first constructed. Explain how the pH of water plays a role in this process.
Please answer it in at least a few sentences!! Thank you!
Which units are used to measure force? newtons feet miles grams
The unit used to measure force is Newton. Therefore, option (A) is correct.
What is the International System of Units?The S.I. units can be defined as the modern version of the metric system and the globally used system of measurement for the different quantities which is established and managed by the Conference on Weights and Measures.
S.I. units system can be demonstrated as a system of measurement used in most of the countries in the world employed in mathematics, technology, industry, science, and commerce.
The S.I. possesses a coherent system of units initiated with seven base units. The second (s) is the unit of time), mole (mol) is the amount of substance, Kilogram (kg) is the unit of mass, meter (m) is length), kelvin (K) is the unit of temperature, ampere (A) is the unit of electric current, and candela (cd) is the luminous intensity.
The force is defined as the mass times of acceleration the unit of mass is Kg and acceleration is m/s². So the unit of the force is Kg.m/s² but we use Newton to measure the force.
Therefore, force is measured in the units of Newton.
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When considering different hypotheses, usually the ____ one which can account for the ____ is the correct one. |
| \/
\/ newest
planetary system simplest
information most complicated
orbitals longest
theory
I know its not chemistry but theres no science option
Answer:
Simplest, Information.
Explanation:
How many valence electrons does Iron (Fe) have? How do you know?
Iron (Fe) has 8 valence electrons, as determined by its position in Group 8 (VIII) of the periodic table, which is a characteristic shared by all elements in this group.
Iron (Fe) has 8 valence electrons.
To determine the number of valence electrons for an element, you can use the periodic table. In the case of iron, it is located in Group 8 (VIII) of the periodic table, also known as Group 8 or Group VIII. The group number indicates the number of valence electrons for elements in that group.
Iron, with its atomic number 26, falls within this group. Elements in Group 8 have 8 valence electrons, as this is the most stable configuration for the outermost electron shell. In the case of iron, it has the electron configuration of 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁶. The 3d subshell contains 6 electrons, and the 4s subshell contains 2 electrons. The sum of these two subshells gives a total of 8 valence electrons.
Valence electrons are important in understanding an element's chemical behavior, as they are involved in chemical bonding and reactions. In the case of iron, its 8 valence electrons play a crucial role in its ability to form chemical bonds and participate in various chemical reactions.
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