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Which non metal is a good conductor of heat and electricity ?

torisob [31]

Answer:

Graphite

Graphite is a non-metal and it is the only non-metal that can conduct electricity. You can find non-metals on the right side of the periodic table and graphite is the only non-metal that is a good conductor of electricity.

4 0

3 years ago

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The decomposition of \rm XY is second order in \rm XY and has a rate constant of6.96Ã10â3M^{-1} \cdot s^{-1} at a certain temper

LUCKY_DIMON [66]

Explanation:

Half life is the amount of time taken by a radioactive material to decay to half of its original value.

Half life for second order kinetics is given by:

$t_{1/2}=\frac{1}{k\times a_0}$

k = rate constant =?

$a_0$ = initial concentration

a = concentration left after time t

Integrated rate law for second order kinetics is given by:

$\frac{1}{a}=kt+\frac{1}{a_0}$

a) Initial concentration of XY = $a_o=0.100 M$

Rate constant of the reaction = k = $6.96\times 10^{-3} M^{-1} s^{-1}$

Half life of the reaction is:

$t_{1/2}=\frac{1}{6.96\times 10^{-3} M^{-1} s^{-1}\times 0.100 M}$

$=1,436.78 s$

1,436.78 seconds is the half-life for this reaction.

b) Initial concentration of XY = 0.100 M

Final concentration after time t = 12.5% of 0.100 M = 0.0125 M

$\frac{1}{0.0125 M}=6.96\times 10^{-3} M^{-1} s^{-1}\times t+\frac{1}{0.100M}$

Solving for t;

t = 10,057.47 seconds

In 10,057.47 seconds the concentration of XY will become 12.5% of its initial concentration.

c) Initial concentration of XY = 0.200 M

Final concentration after time t = 12.5% of 0.200 M = 0.025 M

$\frac{1}{0.025 M}=6.96\times 10^{-3} M^{-1} s^{-1}\times t+\frac{1}{0.200M}$

Solving for t;

t = 5,028.73 seconds

In 5,028.73 seconds the concentration of XY will become 12.5% of its initial concentration.

d) Initial concentration of XY = 0.160 M

Final concentration after time t = $6.20\times 10^{-2} M$

$\frac{1}{6.20\times 10^{-2} M}=6.96\times 10^{-3} M^{-1} s^{-1}\times t+\frac{1}{0.200M}$

Solving for t;

t = 1,419.40 seconds

In 1,419.40 seconds the concentration of XY will become $6.20\times 10^{-2} M$ .

e) Initial concentration of $SO_2Cl_2= 0.050 M$

Final concentration after time t = x

t = 55.0 s

$\frac{1}{x}=6.96\times 10^{-3} M^{-1} s^{-1}\times 55.0 s+\frac{1}{0.050 M}$

Solving for x;

x = 0.04906 M

The concentration after 55.0 seconds is 0.04906 M.

f) Initial concentration of XY= 0.050 M

Final concentration after time t = x

t = 500 s

$\frac{1}{x}=6.96\times 10^{-3} M^{-1} s^{-1}\times 500 s+\frac{1}{0.050 M}$

Solving for x;

x = 0.04259 M

The concentration after 500 seconds is 0.0.04259 M.

7 0

3 years ago

If an atom has 26 electrons, what is the least number of energy levels it has?

kvasek [131]

4 ? each one holds 8

6 0

4 years ago

How many protons, electrons, and neutrons does the following isotope contain?

ASHA 777 [7]

Answer:

Explanation:

An atom is composed of a nucleus and electrons orbiting around it,and the nucleus itself contains protons and neutrons (with the exception of protium, an isotope of hydrogen with only a proton in the nucleus) because each element contains a specific and unique number of protons, but the number of neutrons can vary,an element, therefore, can have several variants, called isotopes, which differ slightly in the composition of the nucleus,the number of electrons can also change in an atom, giving us positive or negative ions.

=Br-79 has 79 nucleons. 79 protons and neutrons. We know that bromine has 35 protons, and 35 electrons, so all we need to do is subtract. 79 nucleons - 35 protons = 44 neutrons,

Subtract the atomic number from the mass number,the result gives you the number of neutrons in the isotope,look to see if the isotope has a charge, denoted by a superscript number and a plus or minus sign next to it,subtract the charge from the atomic number if the charge is positive,the result is the number of electrons in the isotope,add the absolute value of the charge to the atomic number if the charge is negative,the result is the number of electrons in the isotope.

= 35 from 79 and you will get 44. 44 is the number of neutrons in the Br-79 isotope.

79-Br+, that means:

It’s still a Br (bromine) atom, so it doesn’t change the number of protons //because changing the number of protons, it won’t be bromine anymore//

So bromine atom has 35 protons

So, isotope means many forms of atoms with the same element, which are different from atomic mass (or more clearly, the number of neutrons) → 79 (this number is shown for the atomic mass) - 35 = 44 neutrons

It has 35 protons, 34 electrons and 44 neutrons. The way to figure this out is - the protons of an element never change. So when you say bromine, you look it up on the Periodic table and you see its atomic number (aka # of protons) is 35. It will always be 35 for bromine. Then you take the charge into account. In this case, the charge is +1. Since protons can’t change, electrons must. One more proton equals one less electron. So 34 electrons. The atomic weight of a number (79 in this case) is = # of protons + # of neutrons. So neutrons = 79 - 35 = 44.

Hope this helps!

3 0

3 years ago

0. Give an example of how an organism can use surface tension.<br><br><br>

Lady_Fox [76]

Answer:

In case of plants surface tension help to support the transpiration pull.

Explanation:

Surface tension is a force that hold the molecules in the surface to minimize the surface area.

During evaporation of excess amount of water from the stomata of leaves of plants by transpiration a surface tension is generated.

The generated surface tension helps to maintain the water column within the xylem tissue by the absorption of water from the soil by the roots.

3 0

4 years ago

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