CHEMISTRY HIGH SCHOOL

Help! answer 7 & 9 please.​
help! answer 7 & 9 please.​ - 1

Answers

Answer 1
Answer:

Answer:

7 : I think it is because heat rises, and to make the hot air balloon ride is the fire torch inside it.

Explanation:

I donno 9

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Which word equation shows lithium oxide being formed from the reaction between oxygen and lithium?1.)oxygen + lithium oxide to lithium2.)lithium + oxygen to lithium oxide3.)oxygen + lithium to lithium + oxide4.)lithium oxide to lithium + oxygen
how many grams of ca(po4)2 would be produced when 1.5 grams of (nh4)3po4 is reacted with an excess of ca(oh)2
As the elements in Group 17 are considered in order of increasing atomic number, the chemical reactivity of each successive element(1) decreases(2) increases(3) remains the same
Lattice energy is an estimate bond of the bond:-conductivity -group -length -strength The answer is *strength*
Air pollution from automobiles and industrial power plants can be a source of chemical weathering due to the formation ofA. soil.B. acid rain.C. iron oxides.D. calcium carbonate.

"For a many-electron atom, which of the following sublevels has the highest energy? A. 3p. B. 3d. C. 3s. D. 4s".

Answers

Empty 4s orbitals are slightly lower in energy than empty 3d orbitals however, in the context of this question, in a many electron atom where the 4s orbitals are filled, they are repelled to a higher energy level than 3d orbitals and hence the answer should be D.

Consider the following generic chemical equation:A + B → C + D

Reactant A contains 85.1 J of chemical energy. Reactant B contains 87.9 J of chemical energy. Product C contains 38.7 J of chemical energy. If the reaction absorbs 104.3 J of chemical energy as it proceeds, how much chemical energy must product D contain? Explain your answer.

Answers

Answer:  238.6 J

Explanation:

According to the law of conservation of energy, energy can neither be created nor be destroyed. It can only be transformed from one form to another.

Endothermic reactions are those in which heat is absorbed by the system and thus the energy of products is higher than the energy of reactants.

For the given reaction:

A+B+energy\rightarrow C+D

Energy of A = 85.1 J

Energy of B = 87.9 J

Energy on reactant side =  Energy of A + Energy of B  + Energy absorbed 85.1 + 87.9 + 104.3 = 277.3 J

Energy on reactant side = Energy on product side = 277.3 J

Energy on product side = Energy of C + Energy of D

277.3 J = 38.7 J  + Energy of D

Energy of D = 238.6 J

Thus chemical energy product D must contain is 238.6 J

The law of conservation of energy states that energy is not created or destroyed during chemical reactions. The total amount of energy in the reactants, plus the energy absorbed during the reaction, must be equal to the total energy of the products.

Product D contains (85.1 J + 87.9 J + 104.3 J) – 38.7 J = 238.6 J of chemical energy.

.Element Z is a neutral element and has 39 protons. What element is it and how many electrons does it have? (Use the periodic table)

Platinum – 78

Yttrium – 39

Argon – 18

There is not enough information given to determine.

Answers

Answer:

Yttrium – 39

Explanation:

Since the element is neutral and has 39 protons s the atomic number of the element must be 39. Yttrium is the only element in the periodic table with atomic number 39.

Atomic number of an element is equal to the number of protons which is equal to the number of electrons. Since the element is neutral, the number of electrons in Yttrium is also 39.  
If the element have 39 protons, that means that his atomic number is 39, being Yttrium the element. And, the number of protons is the same of the number of electrons, so, 39 electrons.

Determine the unknown mineral using the information given below. Be sure to use significant figure rules when doing calculations. Mass is shown on the triple beam. Scale Test Mineral Mineral H. Density, g/cc 10 diamond tellurium 2 2.07 9 corundum galena 2.5 7.58 8 topaz anglesite 2.5 - 3 6.4 7 quartz chalcocite 2.5 - 3 5.6 6 feldspar copper 2.5 - 3 9.0 5 apatite gold 2.5 - 3 19.3 4 fluorite silver 2.5 - 3 10.5 3 calcite arsenic 3.5 5.7 2 gypsum barite 3 - 3.5 4.4 1 talc dolomite 3.5 - 4 2.9 platinum 4.5 21.5 willemite 5.5 4.0 magnetite 6 5.18 pyrite 6 - 6.5 5.02 pyrolusite 6 - 6.5 5.0 cassiterite 6.5 6.9 diamond 10 3.52 Volume of water displaced = 0.175 L Mass: g Density. g/cm³ Hardness: = - Determine the unknown mineral. Unknown mineral:

Answers

The unknown mineral is likely "barite" due to its density of approximately 0.0251 g/cm³, which closely matches the calculated density of the unknown mineral.

To determine the unknown mineral, we can use the given information about its mass, volume of water displaced, and density. Here are the steps to find the unknown mineral:

1. Calculate the density of the unknown mineral using the formula: Density (g/cm³) = Mass (g) / Volume (cm³).

2. Use the density value to identify the mineral from the provided list.

Given:

- Mass of the unknown mineral = mass on the triple beam = 4.4 g

- Volume of water displaced = 0.175 L = 175 cm³ (since 1 L = 1000 cm³)

Now, calculate the density of the unknown mineral:

Density (g/cm³) = Mass (g) / Volume (cm³)

Density = 4.4 g / 175 cm³ = 0.0251 g/cm³

The density of the unknown mineral is approximately 0.0251 g/cm³. Now, let's find the mineral with a similar density from the provided list:

Among the given minerals, the closest density match is with "barite." Barite has a density of approximately 4.4 g/cm³, which is quite close to the calculated density of the unknown mineral.

Therefore, the unknown mineral is likely "barite."

For more such questions on Mineral Identification

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Answer:

Mass: 981.0 g

Density: 5.61 g/cm^3

Hardness: = 2.5 - 3

Unknown material: Chalcocite

I just got a 100 on the test ^ so that is right

Indicate one use of Nuclear fission,Nuclear fussion ,Half-life of a nuclide​

Answers

Nuclear fission is commonly used in nuclear power plants to generate electricity. The advantage of nuclear fusion is that it has the potential to produce large amounts of energy with minimal waste and no greenhouse gas emissions.

The half-life of a nuclide is crucial for a number of purposes, such as determining the age of archaeological artifacts and determining whether or not the storage of radioactive waste is safe.

The process of breaking up an atomic nucleus into two or more smaller nuclei and releasing a lot of energy is known as nuclear fission. The fission process uses energy to heat water and make steam, which drives turbines that turn into electricity.

The utilization of atomic splitting in power plants enjoys the benefit of delivering a lot of energy with somewhat modest quantities of fuel, and it doesn't discharge ozone depleting substances.

The process of combining two atomic nuclei into a single, more massive nucleus with the release of a significant amount of energy is known as nuclear fusion. This natural process is being investigated as a potential source of energy on Earth and in other stars.

The time it takes for half of a given amount of a radioactive substance to decay is known as the half-life of a nuclide. Scientists can calculate how much of a substance will remain after a certain amount of time by knowing its half-life, allowing them to make educated decisions regarding its safe handling.

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Which scientist is credited with developing the first scientific atomic theory?

Answers

Answer:

John Dalton

Explanation:

John Dalton was the first scientist to give the atomic theory. According to Dalton:

  • All substance is made up of atoms and atoms are indivisible.  
  • All atoms of an element have the same mass.  
  • A compound is formed by the combination of different atoms from different elements.  
  • A chemical reaction is the rearrangement of atoms.  
Dalton was the first scientist to create an atomic theory but he wasn't given any credit. J.J Thompson was credited for his theory (apple pudding)
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