Please help me ! Thank you

Answer:

Explanation:

The percentage error of a certain measurement can be found by using the formula

[tex]P(\%) = \frac{error}{actual \: \: number} \times 100\% \\ [/tex]

From the question

actual density = 19.30g/L

error = 20.9 - 19.3 = 1.6

We have

[tex]p(\%) = \frac{1.6}{19.3} \times 100 \\ = 8.290155440...[/tex]

We have the final answer as

Hope this helps you

Answer:

266Lr

Thirteen isotopes of lawrencium are currently known; the most stable is 266Lr with a half-life of 11 hours, but the shorter-lived 260Lr (half-life 2.7 minutes) is most commonly used in chemistry because it can be produced on a larger scale.

Explanation:

hopefully that helps you

Answer:

19. Option B. ⁰₋₁B

20. Option D. ²¹⁰₈₄Po

Explanation:

19. ²²⁸₈₈Ra —> ²²⁸₈₉Ac + ʸₓZ

Thus, we can determine ʸₓZ as follow:

228 = 228 + y

Collect like terms

228 – 228 = y

y = 0

88 = 89 + x

Collect like terms

88 – 89 = x

x = –1

Thus,

ʸ ₓZ => ⁰₋₁Z => ⁰₋₁B

²²⁸₈₈Ra —> ²²⁸₈₉Ac + ʸₓZ

²²⁸₈₈Ra —> ²²⁸₈₉Ac + ⁰₋₁B

20. ᵘᵥX —> ²⁰⁶₈₂Pb + ⁴₂He

Thus, we can determine ᵘᵥX as follow:

u = 206 + 4

u = 210

v = 82 + 2

v = 84

Thus,

ᵘᵥX => ²¹⁰₈₄X => ²¹⁰₈₄Po

ᵘᵥX —> ²⁰⁶₈₂Pb + ⁴₂He

²¹⁰₈₄Po —> ²⁰⁶₈₂Pb + ⁴₂He

Answer:

C3Br6

Explanation:

C= (1 X 12.011) = 12.011

Br= (2 X 79.904)= 159.808

159.808+12.011 = 171.819

515.46 divided by 171.819 = 3.00

so you mulitpy CBr2 by 3 which gives you C3Br6

Answer:

b is the correct answer

do not trust answer one

Explanation:

Answer:

Elements are the simplest complete chemical substances. Each element corresponds to a single entry on the periodic table. An element is a material that consists of a single type of atom. Each atom type contains the same number of protons.

Chemical bonds link elements together to form more complex molecules called compounds. A compound consists of two or more types of elements held together by covalent or ionic bonds.

Explanation:

Answer:

Thermal equilibrium stops the transfer of energy in just one direction when both objects reach the same temperature, but allows their particles to continue transferring that energy back and forth.

Explanation:

a. The transfer of energy occurs until both objects reach thermal equilibrium. But particles are always moving and crashing with each other. TRUE.

b. The heat transfer occurs from the hotter object to the colder one but moving of particles descreases with temperature decreasing. FALSE.

c. Plastic and wood have a poor quality to transfer energy but there is no material that "stops" perfectly the transfer of energy. FALSE.

d. The heat is transferred from the particles of the hotter object to the particles of the colder one. FALSE

Answer:

Natural Selection

Explanation:

Answer:

The correct answer is 0.67 g H₂

Explanation:

Isopropyl alcohol (C₃H₇OH) can decompose to give acetone (C₂H₆OH) and hydrogen gas (H₂) according to the following chemical equation:

C₃H₇OH (g) ⇒ C₂H₆CO(g) + H₂(g)

We can calculate the initial mass of isopropyl alcohol from the density and volume data:

density = m/V = 0.785 g/mL

⇒ m = density x V = 0.785 g/mL x 25.6 mL = 20.096 g C₃H₇OH

According to the chemical equation 1 mol of C₃H₇OH gives 1 mol H₂. The molar mass of C₃H₇OH is:

molar mass C₃H₇OH = (12 g/mol x 3) + (1 g/mol x 7) + 16 g/mol + 1 g/mol = 60 g/mol

molar mass H₂ = 1 g/mol x 2 = 2 g/mol

So, we obtain: 2 g H₂ from 60 g C₃H₇OH. We multiply this stoichiometric ratio (2 g H₂/60 g C₃H₇OH) by the initial mass of C₃H₇OH to obtain the mass of H₂ is formed:

20.096 g C₃H₇OH x (2 g H₂/60 g C₃H₇OH) = 0.6698 g ≅ 0.67 g H₂

Fe(s) would have the greatest ductility.

Ductility is the capability of a fabric to be drawn or plastically deformed without fracture. it's far therefore a demonstration of how 'gentle' or malleable the fabric is. The ductility of steel varies relying on the sorts and levels of alloying factors gift.

Ductility is the property of metallic associated with the capability to be stretched into twine without breaking. Malleability is the assets of metallic associated with the ability to be hammered into thin sheets without breaking. The outside force or strain is tensile pressure.

Learn more about ductility here https://brainly.com/question/496496

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Answer:

stratosphere

Explanation:

contains a high concentration of ozone in relation to other parts of the atmosphere, although still small in relation to other gases in the stratosphere.

Answer:

stratosphere

Explanation: Most atmospheric ozone is concentrated in a layer in the stratosphere, about 9 to 18 miles (15 to 30 km) above the Earth's surface. Ozone is a molecule that contains three oxygen atoms.

Answer:

1.45g of FeCl3

Explanation:

The equation of the reaction is given as;

2Fe + 3Cl2 --> 2FeCl3

2 mol of Fe reracts with 3 mol of Cl2 to form 2 mol of FeCl3

Upon converting to mass using;

Mass = Number of moles * Molar mass

( 2 * 55.85 = 111.7g ) of Fe reacts with ( 3 * 71 = 213g ) of Cl2 to form ( 2 * 162.2 = 324.4g) of FeCl3

Cl2 is the limiting reactant as it determines how much of FeCl3 is formed

213g of Cl2 = 324.4g of FeCl3

0.950g of Cl2 = x

x = (0.950 * 324.4 ) / 213

x = 1.45g of FeCl3

Answer:

Chromatography involves solvent separation on a solid medium.

Distillation takes advantage of differences in boiling points.

Evaporation removes a liquid from a solution to leave a solid material.

Filtration separates solids of different sizes.

Explanation:

Answer:

C. Milk boils at about 212F

Explanation:

The principal constituents of milk are water, fat, proteins, lactose (milk sugar) and minerals (salts). Milk also contains trace amounts of other substances such as pigments, enzymes, vitamins, phospholipids (substances with fatlike properties), and gases.

Answer:

I'm on the exact same queston

Answer:

The test variable (independent variable) controls the outcome variable (dependent variable)

Explanation:

its right on study island

Answer:

C is for carbon and O is for oxygen

Answer:

Waves is the disturbance or variation that transfer energy from one location to other

Answer:

this is not in my words but i think this will help

(put some of the words you would use in this)

Explanation:

Transverse waves are always characterized by particle motion being perpendicular to wave motion. A longitudinal wave is a wave in which particles of the medium move in a direction parallel to the direction that the wave moves. ... Longitudinal waves are always characterized by particle motion being parallel to wave motion.

hope i helped

Answer:

1 gram of N2 is equal to 0.035697202053303 mole. i dont know the rest but intried to help

. hopefully this will give you someone else a starting point. goodluck

Answer:

8

Explanation:

7 is neutral any anything above it is basic and anything below is acidic which means 8 would be the lowest base

Answer:

The pH of a weak base falls somewhere between 7 and 10.

Explanation:

Like weak acids, weak bases do not undergo complete dissociation; instead, their ionization is a two-way reaction with a definite equilibrium point

Answer:

Explanation:

Materials are clothes and heavy rope

Answer:

Ca(ClO₃)₂(s)      →      CaCl₂(s) + 3O₂(g)

Explanation:

Chemical equation:

Ca(ClO₃)₂(s)      →      CaCl₂(s) + O₂(g)

Balance chemical equation:

Ca(ClO₃)₂(s)      →      CaCl₂(s) + 3O₂(g)

Step 1:

Ca(ClO₃)₂(s)      →      CaCl₂(s) + O₂(g)

Left hand side                     Right hand side

Ca = 1                                     Ca = 1

Cl = 2                                     Cl = 2

O =  6                                     O = 2

Step 2:

 Ca(ClO₃)₂(s)      →      CaCl₂(s) + 3O₂(g)

Left hand side                     Right hand side

Ca = 1                                     Ca = 1

Cl = 2                                     Cl = 2

O =  6                                     O = 6

Answer:

Is like for solving for the solution for both equations??

Answer:

[tex]Total = 50.6\ moles[/tex]

Explanation:

Given

[tex]Propane = C_3H_8[/tex]

Represent Carbon with C and Hydrogen with H

[tex]C = 13.8[/tex]

Required

Determine the total moles

First, we need to represent propane as a ratio

[tex]C_3H_8[/tex] implies

[tex]C:H = 3:8[/tex]

So, we're to first solve for H when [tex]C = 13.8[/tex]

Substitute 13.8 for C

[tex]13.8 : H = 3 : 8[/tex]

Convert to fraction

[tex]\frac{13.8}{H} = \frac{3}{8}[/tex]

Cross Multiply

[tex]3 * H = 13.8 * 8[/tex]

[tex]3 H = 110.4[/tex]

Solve for H

[tex]H = 110.4/3[/tex]

[tex]H = 36.8[/tex]

So, when

[tex]C = 13.8[/tex]

[tex]H = 36.8[/tex]

[tex]Total = C + H[/tex]

[tex]Total = 13.8 + 36.8[/tex]

[tex]Total = 50.6\ moles[/tex]

Answer:

Sugar can't enter cells directly , so when blood sugar level rises, ... signal for the release of insulin into the bloodstream.

Explanation:

yes when the sugar enter the bloodstream it may slowly slowly effect in your body and it may causes diabetes

Answer:

k Nishant

Explanation:

i don't know sorry but u can search in google

Answer:

The answer is

[tex] \huge 7.40 \times {10}^{21} Hz[/tex]

Explanation:

To find the frequency of the wave we use the formula

[tex]f = \frac{E}{h} \\ [/tex]

where

E is the energy

f is the frequency

h is the Planck's constant which is

6.626 × 10-³⁴ Js

From the question

E = 4.90 × 10-¹² J

So we have

[tex]f = \frac{4.90 \times {10}^{ - 12} }{6.626 \times {10}^{ - 34} } \\ [/tex]

We have the final answer as

[tex]7.40 \times {10}^{21} \: \: Hz[/tex]

Hope this helps you

Answer:

D. Electrons: Negative.

Explanation:

Hello, happy to help you today!

In this case, by considering the Bohr's atomic model in which atom is composed by a nuclei containing both protons and neutrons which are positively and neutrally charged respectively and surrounding electrons assembled in orbits or levels of energy which are negatively charged in order to provide a balance to the atom, the correct statement is: D. Electrons: Negative. Also consider the Bohr's model on the attached picture.

My best regards to you!

Explanation:Thermal energy, or heat, is the energy that comes from the movement of atoms and molecules in a substance. Heat increases when these particles move faster. Geothermal energy is the thermal energy in the earth. Motion energy is energy stored in the movement of objects.

I hope this helped!