PLEASE HELP!! 25 points!! Are these sentences true or false

1.) A machine with a mechanical advantage greater than 1 multiplies force

2.)A machine with mechanical advantage less than 1 multiplies distance

This problem is giving information about the proton concentrations of three solutions at 25 °C. Despite they are not numerically given, we can propose three scenarios to see how to approach the question.

Let the following solutions to come up:

[H⁺] = 2.63x10⁻³ M

[H⁺] = 1.00x10⁻⁷ M

[H⁺] = 4.511x10⁻⁹ M

The first step, will be the calculation of the pH for each solution via:

pH = -log([H⁺])

So that they turn out to be:

pH = -log(2.63x10⁻³ M) = 2.580

pH = -log(1.00x10⁻⁷ M) = 7.000

pH = -log(4.511x10⁻⁹ M) = 8.3457

In such a way, since acidic solutions have a pH below 7, neutral have a pH equal to 7 and basic have it above 7, we infer the first one is acidic, second one is neutral and third one is basic.

Thus, you can reproduce this methodology with the proton concentrations you are given.

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Answer:

Physical changes can be classified as reversible or irreversible. Melting is an example of a reversible physical change.

Explanation:

Answer:

atomos

Explanation:

2,500 years ago, Democritus suggested that all matter in the universe was made up of tiny, indivisible, solid objects he called "atomos." However, other Greek philosophers disliked Democritus' "atomos" theory because they felt it was illogical.

Answer is: the partial pressure of the hydrogen 500 mmHg.

p(total) = 523.8 mmHg.

p(water) = 23.8 mmHg.

p(total) = m(water) + p(hydrogen).

p(hydrogen) = p(total) - p(water)..

p(hydrogen) = 523.8 mmHg - 23.8 mmHg.

p(hydrogen) = 500 mmHg.

mmHg or millimeter of mercury is a manometric unit of pressure.

Answer:

36. B, LATTICE

35. A, COVALENT

38. B, TRIPLE COVALENT

Explanation:

36: Lattice- Sodium chloride is taken as a typical ionic compound.

35. covalent - the interatomic linkage that results from the sharing of an electron pair between two atoms. The binding arises from the electrostatic attraction of their nuclei for the same electrons.

38. TRIPLE COVALENT- because each nitrogen atom needs three electrons to fill its outermost shell.

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I hope it help

Answer:

C. the length of the string

Explanation:

Answer:

C. the length of the string

Explanation:

Answer:

Its l and ll

Explanation:

it doesn't mix with moisture that would be sulfurous smog

Answer: 1 and 3

qwq rawr

Explanation:

Mix cold water and flour in a jar. Stir very well. After a few minutes, you can see sediments

at the bottom of the jar. How could you separate the sediments from the water?

3. After the members of the family ate different kinds of fruits, you gathered the seeds. You

mixed them in a basin. Later on, your mother instructed you to separate each kind of seed.

How will you separate each kind of seed?

4. Mix sand and water in a basin. After five minutes, try to separate the sand from the water.

How will you do this?

5. Dissolve one teaspoon of sugar in a cup of water (mixture of solid and liquid.) After three

minutes, separate the sugar from the water. How will you do it?

SANA PO MASAGOTAN NYU NG TAMA

Answer:

5.57 x 10^24 atoms

Explanation:

first, you are seeking the number of ATOMS of Boron.

Boron has an Atomic mass of 10.8 g/mol (see #5 on the periodic table)

100 gm of Boron would have 100 g /10.8 g/mol =9.26 moles

each mole has Avogadros number of atoms 6.02 x 10^23

9.26 moles has 9.26 x 6.02 x 10^23 atoms =5.57 x 10^24 atoms

Answer:

50g iron comprises 5.376 × 1023 atoms.

Explanation:

[tex]2\text{Cr(NO}_3\text{)}_3} + 3\text{CuCl}_2 \longrightarrow 2\text{CrCl}_3 + 3\text{Cu(NO}_3\text{)}_2[/tex]

it's a balance between that reaches the earth and the sun.

Can I have brainlist please

Answer:(8.5d) A compound has a formula Mg:(PO.). Which best describes the atoms that make up this compound? A. B. Atom Magnesium (Mg) phosphorus (0) Oxygen (0)

Explanation:

Answer: 82.0 g/mole

Explanation:

Use the units to see that if we divide 1.64 grams by 0.0200 moles, we'll get a number that is grams/mole, the definition of formula mass.

1.64/0.0200 = 82.0 g/mole (3 sig figs)

We can't tell from this alone what the molecular formula might be, but C6H10 (cyclohexene) comes close (82.1 grams/mole).

The formula mass of the compound will be approximately 82.0 g/mol

The formula mass of the compound is the sum of atomic masses of all the atoms in its chemical formula. It is calculated by adding up the atomic masses of the individual elements in the compound, each multiplied by the subscript indicating the number of atoms of that element in the formula.

To find the formula mass of the compound, we'll use the relationship between moles, mass, and molar mass.

Molar mass (in g/mol) = Mass (in g)/Moles

Given:

Mass = 1.64 g

Moles = 0.0200 moles

Let's plug the values and calculate molar mass:

Molar mass = 1.64 g / 0.0200 moles

Molar mass ≈ 82.0 g/mol

The formula mass of the compound is approximately 82.0 g/mol, rounded to three significant figures.

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The products of the reaction are Zinc chloride (ZnCl₂) and Hydrogen gas (H₂)

From the question,

We are to determine the product or products when zinc (Zn) reacts with hydrochloric acid (HCl)

To determine the product or products, we will write the chemical equation for the reaction.

The balanced chemical equation for the reaction is

Zn + 2HCl → ZnCl₂ + H₂

Hence, the products of the reaction are Zinc chloride (ZnCl₂) and Hydrogen gas (H₂)

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Answer:

Fe3^+

[tex]fe3 ^{ + } [/tex]

Answer:

The energy levels or electron shells of an atom.

Answer:

Each ring represents a different energy level for the electrons. Each ring has a maximum number of electrons that it can hold. The first (inner) ring can only hold two electrons, the second level can hold eight, the third can hold 18 and the fourth holds 32.

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Answer:

because they are saturated

The aspects not accounted for in the ideal gas law are the force of attraction of the gas molecules on each other and the volume of the gas molecules.

So, the aspects not accounted for in the ideal gas law are the force of attraction of the gas molecules on each other and the volume of the gas molecules.

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Answer:

interactions between molecules

size of molecule

(a) The work done by the nitrogen against external pressure is 126.66 J.

(b) The change in the internal energy of the system is -2,466.66 J.

The given parameters:

The molar mass of the given compound is calculated as follows;

NaN₃ = 23+ (14 x 3) = 65 g/mol

65 g -------------- 42

2.25 g ------------- ?

[tex]= \frac{2.25 \times 42}{65} \\\\= 1.45 \ g[/tex]

The volume of the nitrogen gas is calculated as follows;

[tex]\rho = \frac{m}{V} \\\\V = \frac{m}{\rho} \\\\V = \frac{1.45}{1.165} \\\\V = 1.25 \ L[/tex]

[tex]V = 0.00125 \ m^3[/tex]

The work done by the nitrogen against external pressure is calculated as follows;

[tex]W = PV\\\\W = 101325 \times 0.00125\\\\W = 126.66 \ J[/tex]

The change in the internal energy of the system is calculated by applying first law of thermodynamics as follows;

[tex]\Delta E = Q - W\\\\\Delta E = (-2,340) - (126.66)\\\\\Delta E = -2,466.66 \ J[/tex]

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Answer:

okay your question in science

Answer:

in the energy and in the principal quantum number (n)

Explanation:

the energy of 3s sub-shell is less than 4s sub-shell

and the principal quantum number of 3s sub-shell (n)= 3 but the principal quantum number of 4s sub-shell (n) = 4

Answer:

The direction of an electric current is by convention the direction in which a positive charge would move. Thus, the current in the external circuit is directed away from the positive terminal and toward the negative terminal of the battery.

Explanation:

Answer:

Electrons always flow in opposite directions. The direction of an electric current is by convention the direction in which a positive charge would move. Electric current flows from higher electric potential to lower electric potential.

Explanation:

Answer:

Charcoal is produced by the incomplete combustion of plant or animal products. The major use of charcoal is for outdoor cooking. The second largest use of charcoal is in industrial applications in the form of activated charcoal. The activation process involves heating the charcoal subjecting it to steam or treating with a chemical to both remove substances that have adhered to it as well as break it down into finer particles and thus increase the surface area. Activated carbon has been used for its adsorptive properties as a ‘universal antidote’ in cases of poisonings, as a filter aid agent, and in decolorization processes.

Considering the definition of ionization energy, the highest ionization energy belongs to the element:

a. Be

b. Ar

c. Cl

Electrons are held in atoms by their attraction to the nucleus, which means that energy is needed to remove an electron from the atom.

You should keep in mind that the electrons of the last layer are always lost, because they are the weakest attracted to the nucleus.

Ionization energy, also called ionization potential, is the necessary energy that must be supplied to a neutral, gaseous, ground-state atom to remove an electron from an atom. When an electron is removed from a neutral atom, a cation with a charge equal to +1 is formed.

In a group, the ionization energy increases upwards because when passing from one element to the bottom, it contains one more layer of electrons. Therefore, the valence layer electrons, being further away from the nucleus, will be less attracted to it and it will cost less energy to pluck them.

In the same period, in general, it increases as you shift to the right. This is because the elements in this way have a tendency to gain electrons and therefore it will cost much more to tear them off than those on the left which, having few electrons in the last layer will cost them much less to lose them.

Considering all the above, from each of the pairs, the highest ionization energy belongs to the element:

a. Be

b. Ar

c. Cl

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Answer:39+30

Explanation:

Answer:

Explanation:

IIA elements in the periodic table are the alkali earth metals