ANSWER THE QUESTION TO GET BRAINLIST

When sunlight travels from the vacuum of space into Earth's atmosphere it slowed down slightly. Explain why and name the light principle involved.

Answer:

Lead can harm production of blood cells and the absorption of calcium needed for strong bones and teeth, muscle movements, and the work of nerves and blood vessels. High lead levels can cause brain and kidney damage.

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Once lead enters the body, it is distributed to organs such as the brain, kidneys, liver and bones. The body stores lead in the teeth and bones where it accumulates over time. Lead stored in bone may be remobilized into the blood during pregnancy, thus exposing the fetus.

Answer:

22.4cm³

Explanation:

Avogadro's law shows that Avogadro's volume is 22.4

Answer:

Vanished completely.

Explanation:

The atoms of starting substances are transformed into the ending substances because the starting substances mixed with each other and turn into new substances. The starting substances i.e. reactants vanished completely when the ending substances means products are formed completely so we can say that the vanishing of ending substance happened when the ending substances are formed.

Answer:

Brick

Explanation:

.................

Answer:

Volume; high temperature and pressure

Explanation:

In an explosive combustion the rapid expansion of the volume causes explosion and the production of high temperature and pressure.

The substance is usually in a confined place and the expansion usually reaches a breaking point in which it is expelled from the space usually accompanied with a loud noise and high amount of temperature and pressure change thereby releasing its gas constituents.

Answer: There are [tex]12.71 \times 10^{-9}[/tex] moles present in [tex]2.11 \times 10^{14}[/tex] molecules of LiBr.

Explanation:

According to the mole concept, there are [tex]6.022 \times 10^{23}[/tex] molecules present in 1 mole of a substance.

Hence, moles in [tex]2.11 \times 10^{14}[/tex] molecules of LiBr are calculated as follows.

[tex]Moles = \frac{2.11 \times 10^{14}}{6.022 \times 10^{23}}\\= 12.71 \times 10^{-9}[/tex]

Thus, we can conclude that there are [tex]12.71 \times 10^{-9}[/tex] moles present in [tex]2.11 \times 10^{14}[/tex] molecules of LiBr.

Answer:

d

Explanation:

pv=nrt

2.5×1.01×10^5×8×10^-3=3×8.31×T

T=

The value of the temperature can be determined by ideal gas law and the temperature will be 0.81 K.

The average kinetic energy of particular atoms and molecules in a system is measured by the temperature.

Ideal gas law explain the relationship between pressure. temperature and volume.

Ideal gas law can be expressed as, PV=nRT.

where, P is pressure. V is volume , n is number of moles ,R is gas constant and T is temperature. It is given that, n= 3 mole, P = 2.5 atm, V = 8 L, T=?, R = 8.31.

Calculation of temperature by using ideal gas law is shown as:

Now, put the values of given data in ideal gas law equation.

T = PV/nR

=2.5×8/3×8.32

= 0.81 K

Therefore, the temperature will be 0.81K.

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Answer:

The correct option is 2.

Explanation:

In a nuclear reaction balanced we have that:

1. The sum of the mass number (A) of the reactants (r) is equal to the sum of the mass number of the products (p) [tex] \Sigma A_{r} = \Sigma A_{p} [/tex]

2. The sum of the atomic number (Z) of the reactants is also equal to the sum of the atomic number of the products [tex]\Sigma Z_{r} = \Sigma A_{p}[/tex]      

So, let's evaluate each option.

1) [tex]^{23}_{11}Na \rightarrow ^{24}_{11}Mg + ^{1}_{1}H[/tex]

The mass number of the reactant is:

[tex]A_{r} = 23 [/tex]

The sum of the mass number of the products is:

[tex] A_{p} = 24 + 1 = 25 [/tex]

This is not the correct option because it does not meet the first condition ([tex] \Sigma A_{r} = \Sigma A_{p}[/tex]).

2) [tex]^{24}_{11}Na \rightarrow ^{24}_{12}Mg + ^{0}_{-1}e[/tex]  

The mass number of the reactant and the products is:

[tex]A_{r} = 24 [/tex]

[tex] A_{p} = 24 + 0 = 24 [/tex]

Now, the atomic number of the reactants and the products are:

[tex]Z_{r} = 11 [/tex]

[tex] Z_{p} = 12 + (-1) = 11 [/tex]      

This nuclear reaction is balanced since it does meet the two conditions for a balanced nuclear equation, ([tex] \Sigma A_{r} = \Sigma A_{p}[/tex] and [tex] \Sigma Z_{r} = \Sigma Z_{p}[/tex]).  

3) [tex]^{24}_{13}Al \rightarrow ^{24}_{12}Mg + ^{0}_{-1}e[/tex]      

The mass number of the reactant and the products is:

[tex]A_{r} = 24 [/tex]

[tex] A_{p} = 24 + 0 = 24 [/tex]

Now, the atomic number of the reactants and the products are:

[tex]Z_{r} = 13 [/tex]

[tex] Z_{p} = 12 + (-1) = 11 [/tex]      

This reaction does not meet the second condition ([tex] \Sigma Z_{r} = \Sigma Z_{p}[/tex]) so this is not a balanced nuclear equation.

4) [tex]^{23}_{12}Mg \rightarrow ^{24}_{12}Mg + ^{1}_{0}n[/tex]

The mass number of the reactant and the products is:

[tex]A_{r} = 23 [/tex]

[tex] A_{p} = 24 + 1 = 25 [/tex]  

This reaction is not a balanced nuclear equation since it does not meet the first condition ([tex] \Sigma A_{r} = \Sigma A_{p}[/tex]).

Therefore, the correct option is 2.

I hope it helps you!

Answer:

33 moles

Explanation:

The given chemical reaction is 2C₄H₁₀(g) + 13 O₂(g) → 10H₂O(g) + 8CO₂(g)

The number of moles of each reactant are as follows;

Butane, C₄H₁₀ = 2 moles of (g) + 13 (g) → 10H₂O(g) + 8CO₂(g)

Oxygen gas, O₂ = 13 moles

Water, H₂O = 10 moles

Carbon dioxide, CO₂ = 8 moles

The total number of moles, n = (2 + 13 + 10 + 8) = 33

∴ The total number of moles involved in the reaction, n = 33 moles.

Answer:

yes I do think they mean the same thing

Explanation:

150 grams and 150 grams is the same thing and adding 0 to the end of a decimal does not change its value, you could even put 150.0000000 grams and it would still be equivalent to the other numbers

Reactivity of non-metals depend on their ability to gain electrons. So, smaller is the size of a non-metal more readily it will attract electrons because then nucleus will be more closer to valence shell. ... Hence, Br is the non-metal which will be more reactive than At.

Answer:

br is more reactive than as

Answer:

16mL

Explanation:

Using the following formula;

CaVa = CbVb

Where;

Where

Ca = concentration/molarity of acid (M)

Va = volume of acid (mL)

Cb = concentration/molarity of base (M)

Vb = volume of base (mL)

According to the information provided in this question;

Ca (HCl) = 2M

Cb (NaOH) = 5M

Va (HCl) = 40mL

Vb (NaOH) = ?

Using CaVa = CbVb

Vb = CaVa/Cb

Vb = 2 × 40/5

Vb = 80/5

Vb = 16mL

From the formula of methane it is clear that one mole of methane has 4hydrogen atoms. So, 37.6×1023 hydrogen atoms are there in 25.0 g of methane. Therefore, 9.4×1023methane molecules and 9.4×1023 hydrogen and 37.6×1023carbon atoms are there in 25.0 g of methane.

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OPTION C is the correct answer.

There are four main factors that can affect the reaction rate of a chemical reaction:

Reactant concentration. Increasing the concentration of one or more reactants will often increase the rate of reaction. ...

Physical state of the reactants and surface area. ...

Temperature. ...

Presence of a catalyst.

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Answer:

Gold and pyrite both have a brilliant metallic luster, but are different tones of yellow. Gold is golden to silvery yellow, whereas pyrite is a pale to medium brassy yellow that sometimes tarnishes.

Explanation:

Answer:

may be the answer is Heat and pressure - melting - cooling

Answer:

The products are already in the question Hydrogen gas and Magnesium Chloride

Explanation:

2Mg +2HCl₂ = 2MgCl₂ + H₂ balanced equation if you need it

When any metal react with acid then salt and hydrogen gas is formed. Hydrogen gas and Magnesium Chloride are formed when Magnesium is added to dilute hydrochloric acid.

Chemical reaction is a process in which two or more than two molecules collide in right orientation and energy to form a new chemical compound. The mass of the overall reaction should be conserved. There are so many types of chemical reaction reaction like combination reaction, double displacement reaction.

The products are Hydrogen gas and Magnesium Chloride. The balanced equation can be written as

Mg +2HCl[tex]\rightarrow[/tex] MgCl₂ + H₂

This makes bubbles of hydrogen and a colorless solution of magnesium chloride.

Therefore Hydrogen gas and Magnesium Chloride are formed when Magnesium is added to dilute hydrochloric acid.

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Answer:

A. Li= 5.6 g O2= 6.4 g

Explanation:

Lithium oxide, Li2O, is an oxide that contains 2 moles of Li and 1 mole of O per mole of oxide. To solve this question we must find the mass of each atom in the molecule as follows:

2Li = 2*6.941g/mol = 13.882g/mol

O = 1*16g/mol = 16g/mol

Molar mass Li2O:

16+13.882 = 29.882g/mol

The mass of lithium is:

12g * (13.882g/mol / 29.882g/mol) = 5.6g Li

And the mass of oxygen:

12g * (16g/mol / 29.882g/mol) = 6.4g O

Right answer is:

Explanation:

Melting is defined as the physical process where a solid state of a substance converts into its liquid state. No change of chemical composition takes place, just the physical state of water is changing.

[tex]\text{Solid}\rightleftharpoons \text{Liquid}[/tex]

There are given carboxylic acids. The melting point of these acids increases to its second group member which is ethanoic acid due to prevalent hydrogen bonding. To break this bonding, a high amount of heat needs to be applied.

But as we move forward, the melting point decreases sharply as an increase in the number of carbon atoms decreases the hydrogen bonding.

Melting point of Formic Acid = [tex]8.3^oC[/tex]

Melting point of Acetic Acid = [tex]16.6^oC[/tex]

Melting point of Propionic Acid = [tex]-21^oC[/tex]

Answer:

2.2)solido

2.3)Sólido cristalino

2.4)Sólido amorfo

Answer:

9

Explanation:

I took the same test :)

The stoichiometry is important in chemistry which helps us to use the balanced equation to calculate the amount of reactants and products. Here the moles of hydrogen needed is 9. The correct option is B.

The quantitative study of the reactants and products involved in a chemical reaction is known as the chemical stoichiometry. The stoichiometric coefficients can be fractions including the whole numbers.  It helps to establish the mole ratio.

The stoichiometric coefficient is basically the number which is present in front of the atoms, molecules or ions. The stoichiometric calculations are also used in gravimetry and volumetry.

Here the balanced equation for the reaction is:

N₂ + 3H₂ → 2NH₃

Number of moles of H₂ = 3 mol N₂× 3 mol H₂  / 1 mol N₂ = 9 mol H₂

So the number of moles of H₂ is 9.

Thus the correct option is B.

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Answer:

333.3mL

Explanation:

Using the formula as follows:

C1V1 = C2V2

Where;

C1 = initial concentration (M)

C2 = final concentration (M)

V1 = initial volume (mL)

V2 = final volume (mL)

According to the information provided in this question,

C1 = 4.00M

C2 = 1.50M

V1 = 125mL

V2 = ?

Using C1V1 = C2V2

4 × 125 = 1.5 × V2

500 = 1.5V2

V2 = 500/1.5

V2 = 333.3mL

Therefore, the CuSO4 solution needs to be diluted to 333.3mL to make 1.50 M solution.

Answer:

425 and 0.28A

Explanation:

Resistance for resistors in parallel

1/ R = 1/250 +1/250

=0.008

R = 1/ 0.008 = 125

Total resistance

R= 125+ 300

=425

...

V= IR

I= V/R

I = 120/425

= 0.28 A

Answer:

3.7 atm

General Formulas and Concepts:

Atomic Structure

Gas Laws

Ideal Gas Law: PV = nRT

Explanation:

Step 1: Define

Identify variables

[Given] n = 0.68 mol H

[Given] T = 298 K

[Given] V = 4.5 L

[Given] R = 0.0821 L · atm · mol⁻¹ · K⁻¹

[Solve] P

Step 2: Find Pressure

Step 3: Check

Follow sig fig rules and round. We are given 2 sig figs as our lowest.

3.69705 atm ≈ 3.7 atm

Answer: The correct option is D) [tex]Ag^+[/tex]

Explanation:

The oxidation reaction is defined as the reaction in which a chemical species loses electrons in a chemical reaction. It occurs when oxidation number of a species increases.

A reduction reaction is defined as the reaction in which a chemical species gains electrons in a chemical reaction. It occurs when oxidation number of a species decreases.

For the given chemical reaction:

[tex]Zn^0+2Ag^+\rightarrow Zn^{2+}+2Ag^0[/tex]

On the reactant side:

Oxidation number of Zn = 0

Oxidation number of Ag = +1

On the product side:

Oxidation number of Zn = +2

Oxidation number of Ag = 0

As the oxidation number of Ag is decreasing from +1 to 0. Thus, [tex]Ag^+[/tex] is getting reduced.

Hence, the correct option is D) [tex]Ag^+[/tex]