Would rust be considered a chemical or physical change? (I know the answer) Answer this first, and you will receive 20pts regardless, and will receive the "Most Brainiest." (I'm just testing you). I will correct any wrong answers. Any answer afterwards, will be for fun. :)

Answer:

Atomic number 29

Atomic mass 63.546 g.mol -1

Electronegativity according to Pauling 1.9

Density 8.9 g.cm-3 at 20°C

Melting point 1083 °C

Copper has a melting point of 1083.4 +/- 0.2°C, boiling point of 2567°C, specific gravity of 8.96 (20°C), with a valence of 1 or 2. Copper is reddish colored and takes a bright metallic luster. It is malleable, ductile, and a good conductor of electricity and heat.

Answer:

6.19⋅109ng

Explanation:

The first thing to do here is to determine the mass in grams of 2.33⋅1020 atoms of oxygen.

To do that, use Avogadro's number to convert the number of atoms to moles, the molar mass of oxygen to convert the moles to grams.

So, Avogadro's number, which acts as the definition of a mole, tells you that in order to have one mole of oxygen, you need to have 6.022⋅1023 atoms of oxygen.

In your case, the sample will be equivalent to

2.33⋅1020 atoms of O ⋅1mole O

                                    6.022⋅1023 atoms of O   =3.869⋅10−4 moles O

Now, oxygen has a molar mass of 15.9994 g mol−1 as listed in the Periodic Table of Elements

This means that your sample will have a mass of

3.869⋅10−4 moles O   ⋅15.9994 g

                                       1 mole O           =6.190⋅10−3g

Finally, you can convert the mass from grams to nanograms by using the conversion factor  

1 g=109ng

You will end up with

6.190⋅10−3g ⋅109ng

                        1g=6.19⋅106ng

meaning The answer is rounded to three sig figs.

Answer:

Thickness, length, and temperature

Explanation:

The resistance of a long wire is greater than the resistance of a short wire because electrons collide with more ions as they pass through. The relationship between resistance and wire length is proportional. A thicker wire simply has more 'lanes' on the go at once. A higher current for a given voltage means a lower resistance. The thicker wire has a lower resistance than the thinner wire does. The resistance of a wire decreases with increasing thickness. The resistance of a metal conductor is due to collisions between the free electrons of the electric current and the metal ions of the wire. If the temperature of a metal conductor increases, the ions of the metal vibrate more vigorously. The resistance of an NTC thermistor decreases with increasing temperature.

The resistance of a wire depends on the following three properties of a wire, thickness, length, temperature.

The resistance of a wire is the opposition to the flow of current offered by the wire.

The resistance of a wire depends on the flowing;

R = ρL/A

where;

Thus, the resistance of a wire depends on the following three properties of a wire, thickness, length, temperature.

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Answer:

For any given element, ionization energy increases as subsequent electrons are removed. For example, the energy required to remove an electron from neutral chlorine is 1251 kJ/mol. ... An even sharper increase in ionization energy is witnessed when inner-shell, or core, electrons are removed.

Hope it helps :)

Answer:

Lateral Inversion

Explanation:

Mass of oxygen gas produced : 14.08 g

Reaction

2H₂O(l)⇒2H₂(g)+O₂(g)

mol of H₂O (MW=18 g/mol) :

[tex]\tt \dfrac{20}{18}=1.1[/tex]

mol O₂ :

[tex]\tt \dfrac{1}{2}\times 1.1=0.55[/tex]

mass O₂ (theoretical) :

[tex]\tt 0.55\times 32=17.6~g[/tex]

mass O₂ (actual) :

[tex]\tt =\%yield\times theoretical\\\\=0.8\times 17.6=14.08[/tex]

Answer: I'm willing to help you find the formula for that ionic crystal but, I can't see anything.

The ionic crystal contains a total of 6 Ba atoms and 6 oxygen atoms. Hence they are in 1 : 1 ratio and the formula of the ionic compound is BaO.

Ionic compounds are formed between metals and non-metals. Ionic bond is formed by the lose of electrons from the metals to the nonmetals. The chemical formula of the ionic compounds are written with the cationic symbol first.

The given ionic crystal is formed with barium and oxygen atoms. Valency of barium is 2 and that of oxygen is also 2. Thus, barium loses two electrons to oxygen forming BaO.

The given crystal lattice consists of 3 barium atoms and 3 oxygen atoms in front face and 3 Ba and 3 o in back face also. Thus, both are 6. They are in the ratio of 1 : 1. Hence, the compound is named as BaO.

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Answer:

21 is ionic aicid only one 1 know

Answer:

False

Explanation:

There is a direct relationship between wave frequency and energy...

The higher the frequency, the higher the energy

alternatively, the lower the frequency, the lower the energy

Answer:

yes

Explanation:

Answer:

D

Explanation:

Units and directions

Answer:

discupaeu não sei

um belo dia abençoado

Answer:

NaCI

Explanation:

Answer:

The atmosphere and Earth's interior are layered by density. ... Earth's core, at its center, is denser than its crust. The lowest layer of the atmosphere is denser than the upper layer. Earth's liquid metal outer core has convection, which generates the magnetic field.

Explanation:

hope this helps!

Answer:

Gravity pulls denser materials to the center of the earth, so it is basically a sphere of wrapping paper that gets denser and denser the more you unwrap the layers. The core is the most dense, and the crust is the least dense.

Hope This Helps! :) Plz Give Brainliest!

Answer:

1) Zn(s) + 2HCl(aq) --> ZnCl2(aq) + H2(g)

You would see the reaction forming bubbles vigorously. Hydrogen gas is produced in the process.

Answer:

B. increase the temperature

Explanation:

Answer:

uhhh well ig btw what plant

Explanation:

it would be more sunlight to

Answer:

D

Explanation:

hope this helps

Answer:

22.95g

Explanation:

Given parameters:

Percentage by mass of silver in silver iodide  = 45.9%

Mass of silver iodide given  = 50g

Unknown:

Mass of silver in silver iodide  = ?

Solution:

The formula of the compound is;

 Silver iodide  = AgI

       Since the percentage by mass of silver in the compound is 45.9%;

 Mass of silver  = percentage by mass of silver x mass of AgI

 Mass of silver  = [tex]\frac{45.9}{100}[/tex] x 50  = 22.95g

Answer:

Gold is an element even when it is in a solution

Answer:

C. He

Explanation:

When lithium is ionized, its new electronic configuration is the same as that of a helium atom.

 Lithium is made up of 3 electrons with a configuration of:

                     2, 1

it has 1 electron in its outermost shell.

As a metal lithium will prefer to lose an electron due to its electropositivity.

    On losing an electron, it will have 2 electrons remaining

Now, Helium has 2 electrons and this makes it similar to Lithium that has lost one electron.

This makes Lithium isoelectronic with Helium.  

Answer:

yes i can anwser

Explanation:

Explanation:

The molar mass of a substance is the mass in grams of one mole of the substance. In a compound, add the atomic masses of the components.

 HCl

 Atomic mass of H  = 1g/mol,  Cl = 35.5g/mol

   HCl  = (1 + 35.5) = 36.5g/mol

 ZnF₂

Atomic mass of Zn  = 65.4g/mol, F = 19g/mol

      ZnF₂  = 65.4 + 2(19) = 103.4g/mol

 K₂CO₃

   Atomic mass of K = 39, C  = 12, O = 16

    K₂CO₃  = 2(39) + 12 + 3(16)  = 138g/mol

 FePO₄

Atomic mass of Fe = 55.8, P = 31, 0 = 16

 FePO₄ = 55.8 + 31 + 4(16) = 150.8g/mol

Cu₂S

  Atomic mass of Cu = 63.5g/mol, S = 32

    Cu₂S = 2(63.5) + 32 = 159g/mol

Each term in the series represents a sinusoidal component with a frequency of (kπ/4) and an amplitude of 4.

To express the given periodic signal x(t) in the form x(t) = ∑[k=0 to infinity] A_k cos(w_kt + ϕ_k),\

we can use the formula for the Fourier series representation of a periodic signal.

1. First, let's find the values of A_k, w_k, and ϕ_k using the given Fourier series coefficients.

The given coefficients are:

a_1 = a_-1* = j

a_5 = a_-5 = 2

Since x(t) is real-valued, the coefficients for negative frequencies (a_-k) are the complex conjugates of the coefficients for positive frequencies (a_k).

From the given coefficients, we can determine the values of A_k:

A_1 = a_1 + a_-1 = j + conj(j) = j - j = 0

A_5 = a_5 + a_-5 = 2 + conj(2) = 2 + 2 = 4

Since the fundamental period T is 8, the fundamental frequency is ω_0 = 2π/T = 2π/8 = π/4.

The values of w_k can be determined as:

w_0 = 0

w_k = k * w_0 = k * (π/4) for k ≠ 0

The values of ϕ_k can be determined as:

ϕ_0 = 0

ϕ_k = arg(a_k) for k ≠ 0

2. Now, let's express x(t) in the desired form using the determined values.

x(t) = A_0 cos(w_0t + ϕ_0) + ∑[k=1 to infinity] A_k cos(w_kt + ϕ_k)

Substituting the values we found:

x(t) = 0 cos(0t + 0) + ∑[k=1 to infinity] 4 cos((kπ/4)t + arg(a_k))

Simplifying:

x(t) = ∑[k=1 to infinity] 4 cos((kπ/4)t + arg(a_k))

This is the expression of x(t) in the desired form.

Remember that the series is infinite, so it includes all integer values of k.

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Answer:

create and destroyed

Explanation:

its just simple science

Answer:

Create bonds

Broken

Explanation:

Energy is required to created bonds in a molecule and released when bonds are broken.

Energy is needed in chemical reactions to do work.

Answer: To your project!!

Experiment Half-Life

a. My hypothesis is that when we get through 6 half-life’s you will be left with no atoms, and each time the atom number will decrease. Half of my hypothesis was correct whilst the numbers did decrease we, after 6 trials were left with one undecayed atom.

b.what is a half life?

the time required for the decay of one-half of the atoms in a sample of radioactive material

c. When does a radioactive sample emit the largest number of decay particles? when it first starts to decay

Why is this information important? Half-Life and decay is important today because it helps us determine the date of death and birth of ancient mummies.

d. Do you think the shape of the curve on your graph would change if you increased the half-life to 20 seconds? Yes different data would arise and that would change the graph.

What does this reveal about radioactive decay? The longer a material or substance takes to decay the larger the amount of decayed material or substance will come from the substance

e. Do you think the shape of the curve on your graph would change if you started with a smaller sample, say 50 atoms (pennies)? Yes, again different data would arise and that would change the graph.

What does this reveal about radioactive decay? The smaller the sample the quicker it will decay. And the less product that comes from the sample.

Your project is done, it worked for me hope it does for you? DON'T USE THE EXACT SAME WORDS IT'S SUS

here is the graph too!

Answer:

Hey I dont know if you got the same project as me but I had to record pennies and make a graph so I recorded pennys here

Explanation:

first half-life =  tails 49 : heads 51

second half-life = tails 19 : heads 29

third half-life = tails 8 ; heads 11

fourth half-life = tails 2 ; heads 6

fifth half-life = tails 1 ; heads 1

sixth half-life = I didnt know what to say so I put 1

hope this helps someone

Answer:

There would be no energy for cellular activities

Explanation:

Cellular respiration is the process whereby living organisms breakdown ingested food in their cells in order to obtain energy in form of ATP. In other words, respiration converts the stores energy in food molecules into usable energy by the cell. The general equation of the process is as follows:

C6H12O6 + 6O2 → 6CO2 + 6H2O

The process of cellular respiration is carried out by every living organism in order to obtain energy to perform their various metabolic activities. Hence, without RESPIRATION, there would be no energy (ATP) for use by the cell, which utterly means no cellular activities will take place.