A piece of metal is composed of atoms Each atom in the metal contains 29 protons how is the metal classified

Answer:

H₂

Explanation:

Answer:

See explanation

Explanation:

This question is obviously supposed to be a multiple choice question but the options are missing.

However, the question intends to test the student's knowledge about combustion of fossil fuels. Fossil fuels are mostly composed of hydrocarbons of different chain lengths.

The longer the chain length, the greater the energy released when the compound is burnt since there are more energy stored in its bonds.

Hence, the correct answer to this question will be the option that contains the greatest number of C-C and C-H bonds.

Answer:

Breast Cancer occurs in a lot of women.

Explanation:

The following are some symptoms of breast cancer in women.

New lump in the breast or underarm (armpit).

Thickening or swelling of part of the breast.

Irritation or dimpling of breast skin.

Redness or flaky skin in the nipple area or the breast.

Pulling in of the nipple or pain in the nipple area.

Nipple discharge other than breast milk, including blood.

Another thing is that women each year after age 40 are encouraged to get a mamogram.

Answer:

yes breast cancer can occur in both men and women.

Explanation:

some warning signs can be feeling a new lump on or around the breast or in the arm pit area, swollen or redness, also discharge from the nipple can be a sign of breast cancer. Breast pain that doesn't go away can be a sign of breast cancer.

hope this helps some. have a great night!

Answer:

the trigger . it's the trigger

Answer:

It is the handle

Explanation:

I know because I did this test in school

Answer:

After 7.648 days, you will see one quarter.

Explanation:

1 → 0.5 → 0.25

Since half life of radon-222 is 3.824 days, you need twice this time to get one quarter at the end.

2 ⋅ 3.824 = 7.648 days.

Answer:

3.7

Explanation:

Significant figures:

All non-zero digits are consider significant figures like 1, 2, 3, 4, 5, 6, 7, 8, 9.

Leading zeros are not consider as a significant figures. e.g. 0.007 in this number only one significant figure present which is 7.

Zero between non zero digits are consider significant such as  1004 consist of four significant figures.

The zeros at the right side such as 4500 are also significant. There are four significant figures are present.

When we add or subtract the values the number of significant figures after decimal in result must be equal to the given measurement having less number of decimal places.

When we multiply or divide the values the number of significant figures must be equal to the less number of significant figures in given value.

Now we will calculate the difference between 7.69 and 4.0.

7.69 - 4.0 = 3.69

In given values 4.0 have less number of decimal places thus result must have only one decimal places. So we would round the result.

3.7

                                Its true im pretty sure

It's true

Hope this helped!

Answer:

False

Explanation:

A mixture is composed of two or more substances that are combined through physical means. It has NOT undergo any changes in its chemical properties. So, even though its appearance change, it can be reverted back.

Answer:

That answer would be false.

Explanation:

Depending on the type of mixture, you can separate it and reverse it back to its original properties through filtration, evaporation, distillation, and chromatography.

Answer: 255 pm

Explanation: Hope this helps!

Answer:

Na(0.93) & F(3.98)

K(0.82) & Cl(3.16)

Cs(0.79) & Br(2.96)

Explanation:

Answer:

Ke = mgv

Explanation:

(60)(9.81)(2) =1177.2 joules persecond or Watts.

1.177 kilowatts

Answer:

Explanation:

(i) Which one of these structures A to E represents a noble gas?

Noble gases have completely filled outer most orbital. It means they have 8 valence electrons. Picture D have 8 valence electrons thus it represent noble gas.

(ii) Which two of these structures represent atoms from the same group of the periodic table?

Atoms present in same group having same number of valence electrons.

Picture A and C both have one valence electron thus both are present in same group.

(iii) Which one of these structures represents an atom with an atomic number of 8?

Picture B have total 8 number of electrons it means this atom have atomic number 8. So answer is picture B.

(iv) Which one of these structures forms a stable ion by gaining one electron?

Ions are formed by gaining or losing the electrons. When an atom gain electron anion is formed. There are 7 electron in outer orbital of picture E when it gain one electron outer orbital become completely filled thus form stable ion.

(v) Which one of these structures is in period 3 of the periodic table?

Picture C have 11 electron it means this atom have atomic number 11 which represent sodium. Sodium is present in period 3. Thus answer is picture C.

When you increase the pressure, the molecules have less space in which they can move. That greater density of molecules increases the number of collisions. When you decrease the pressure, molecules don't hit each other as often and the rate of reaction decreases. Pressure is also related to concentration and volume.

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Answer:

What are the Answer choices

Answer:

Electrolysis of Al₂O₃: 4Al³⁺ (s) + 6O²⁺ (g) → 4Al (s) + 3O₂ (g)

Reduction of Elemental Fe: 2Fe₂O₃ (s) + 3C (s) → 4Fe (s) + 3CO₂ (g)

Atom Economy for Electrolysis of Al₂O₃: 52.9227%

Atom Economy for Reduction of Fe₂O₃: 62.8534%

Explanation:

Step 1: Define Compounds

Aluminum Oxide - Al₂O₃

Iron Oxide - Fe₂O₃

Step 2: RxN

Al₂O₃ (s) → Al (s) + O₂ (g)

Fe₂O₃ (s) + C (s) → Fe (s) + CO₂ (g)

Step 3: Balance RxN

2Al₂O₃ (s) → 4Al (s) + 3O₂ (g)

This is ONLY the decomposition reaction for Aluminum oxide, NOT the electrolysis.

2Fe₂O₃ (s) + 3C (s) → 4Fe (s) + 3CO₂ (g)

This is the final single-replacement reaction for the reduction of Iron Oxide to Iron.

Step 4: Electrolysis of Al₂O₃

We will have to use oxidation-reduction reactions (half-reactions). Let's break up the reaction into it's elements.

Al³⁺ + ? → Al

Al³⁺ + 3e⁻ → Al

O²⁻ → O₂ + ?

2O²⁻ → O₂ + ?

2O²⁻ → O₂ + 4e⁻

Our half reactions:

Al³⁺ + 3e⁻ → Al

2O²⁻ → O₂ + 4e⁻

4 (Al³⁺ + 3e⁻ → Al) = 4Al³⁺ + 12e⁻ → 4Al

3 (2O²⁻ → O₂ + 4e⁻) = 6O²⁻ → 3O₂ + 12e⁻

4Al³⁺ + 12e⁻ + 6O²⁺ → 4Al + 3O₂ + 12e⁻

4Al³⁺ (s) + 6O²⁺ (g) → 4Al (s) + 3O₂ (g)

Step 5: Atom Economy

According to GCSE and my own deciphering, your equation for Atom Economy is essentially calculating for something similar to percent yield (but not quite).

[tex]Atom \hspace{3} Economy \hspace{3} = \hspace{3} \frac{Molar \hspace{3} Mass \hspace{3} of \hspace{3} Product}{Molar \hspace{3} Mass \hspace{3} of \hspace{3} All \hspace{3} Reactants} \cdot 100 \%[/tex]

Molar Mass of Al - 26.98 g/mol

Molar Mass of O - 16.00 g/mol

Reactants: 4(26.98 g/mol) + 6(16.00 g/mol) = 203.92 g/mol

Products (Al as end product): 4(26.98 g/mol) = 107.92 g/mol

[tex]Atom \hspace{3} Economy \hspace{3} = \hspace{3} \frac{107.92 \hspace{3} g/mol}{203.92 \hspace{3} g/mol} \cdot 100 \%=52.9227 \%[/tex]

Molar Mass of Fe - 55.85 g/mol

Molar Mass of O - 16.00 g/mol

Molar Mass of C - 12.01 g/mol

Reactants: 4(55.85 g/mol) + 6(16.00 g/mol) + 3(12.01 g/mol) = 355.43 g/mol

Products (Fe as end product): 4(55.85 g/mol) = 223.4 g/mol

[tex]Atom \hspace{3} Economy \hspace{3} = \hspace{3} \frac{223.4 \hspace{3} g/mol}{355.43 \hspace{3} g/mol} \cdot 100 \%=62.8534\%[/tex]

Step 6: Check for significant figures

Since we are not given any values, we don't really need to change any numbers to fit sig fig rules.

Answer:

Al2 O3 or 2:3

Explanation:

The aluminum oxide consists of two elements, which are oxygen atoms and aluminum atoms, and there are 2 aluminum atoms and 3 oxygen atoms in aluminum oxide. The ratio from aluminum atoms to oxygen atoms is 2:3.

There are two types of chemical compound one is covalent compound and other is ionic compound, covalent compound formed by sharing of electron and ionic compound formed by complete transfer of electron. Therefore, the ratio of aluminum atoms to oxygen atoms in aluminum oxide is  2:3.

Chemical Compound is a combination of molecule, Molecule forms by combination of element and element forms by combination of atoms in fixed proportion.

An ionic compound is a metal and nonmetal combined compound.  Ionic compound are very hard. They have high melting and boiling point because of strong ion bond. The ratio of aluminum atoms to oxygen atoms in aluminum oxide is  2:3. Aluminium oxide is an ionic compound.

Therefore, the ratio of aluminum atoms to oxygen atoms in aluminum oxide is  2:3.

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Answer:

Oxgen- cannot be separated

Water - chemical change

Gold - cannot be separated

Carbon Dioxide - chemical change

Carbon​ - cannot be separated

Explanation:

A pure substance, which can either be an element or a compound, contains only one type of such element or compound. In opposition to a mixture, pure substances cannot be separated by physical means.

- Elements as a pure substance cannot be separated because it contains only one type of atom. However, compounds contain two or more types of atoms, and hence, can only be separated into its individual atoms via chemical means.

In this question, oxygen (O2), Gold (Au) and carbon (C) are all elements and hence cannot be separated. Carbon dioxide (CO2) and water (H2O) are compounds because they contain two different atoms respectively, hence, can be separated into individual atoms.

Answer:

it can show how much green is left. and how climate change is going, and the cloud shows how much oxygen is left in the air.

Answer:

CO2 is a compound cause there is more then one

Answer:

Explanation:

To find the number of moles in a substance given it's number of entities we use the formula

[tex]n = \frac{N}{L} \\ [/tex]

where n is the number of moles

N is the number of entities

L is the Avogadro's constant which is

6.02 × 10²³ entities

From the question we have

[tex]n = \frac{4.5 \times {10}^{24} }{6.02 \times {10}^{23} } \\ = 7.47508...[/tex]

We have the final answer as

Hope this helps you

Answer:

The correct option is;

(B) [tex]\Delta H_{mix} < 0[/tex], solution shows negative deviation

Explanation:

The given parameters are;

The available volume of liquid A = 25 cm³

The available volume of liquid B = 20 cm³

The volume of the solution (mixture) = 44.8 cm³

Therefore, we have;

[tex]\Delta _{mix} V < 0[/tex]

Which is one of the prerequisite for the formation of negative deviation

When a non-ideal solution shows negative deviation according to Raoult's Law, we have;

[tex]\Delta _{mix} H < 0[/tex], we have more heat released due to new molecular interactions.

Answer:

A

Explanation:

Solid particles only vibrate, so they have very little kinetic energy.

For B, the size of the particles stay the same, just phase/state changes, so not B.

For C, gas particles move the fastest compared to liquid and solid given the same environment.

For D, they don't have the same kinetic energy because solid particles barely move while gas particles keep moving.

Answer:

Explanation:

Physical change is easily reversible. Burning/combustion is a chemical process where substances react rapidly with oxygen: this is usually irreversible.

The marshmallow, roasted food and burned wood all undergo combustion and hence are tagged chemical changes.

I hope this helps.

Answer:

Chopping Wood

Heating Water

Explanation:

Answer:

for more details are in the pic

Phosphorus pentoxide is a white solid that has no noticeable smell. This substance has the chemical formula P₄O₁₀. But its name comes from its empirical formula, P₂O₅. Here the correct option is B.

This substance is a white solid with a crystalline structure at room temperature. An acid anhydride made from phosphoric acid is phosphorus pentoxide. Due to its strong hygroscopicity, it is employed as a desiccant and a dehydrating agent.

When in contact with water, phosphorus pentoxide hydrolyzes quickly and violently. This reaction produces a lot of heat. The four polymorphs of this chemical that crystallize are different. Because it is so corrosive, metals must be kept away from it.

Thus the correct option is B.

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Answer:

351.43mL

Explanation:

To calculate the original volume of hydrogen gas in this question, the Boyle's law equation will be used. Boyle's law equation is:

P1V1 = P2V2

Where; P1 = initial pressure

V1 = initial volume

P2 = final pressure

V2 = final volume

According to this question, the P1= 1.56atm, V1 = ?, P2 = 0.73atm, V2 = 751mL

Hence;

P1V1 = P2V2

1.56 × V1 = 0.73 × 751

1.56 V1 = 548.23

V1 = 548.23/1.56

V1 = 351.43mL

Therefore, the original volume of hydrogen gas is 351.43 mL.

The characterization of the following statements with respect to intensive or extensive is as follows:

Extensive may be defined as terminology that illustrates any event or action which is extremely large and significantly found at the outer level of any referring details. For example, the shipping cost of a book (depends on weight) is mentioned outside the cover of the book.

Intensive may also be characterized as a scientific terminology that significantly deals with any object or details which is present inside the content. For example, the number of pages in a book is mentioned inside the book.

Therefore, the characterization of the following statements with respect to intensive or extensive is appropriately described above.

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