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3 years ago

Atomic emission spectra are unique to each element. true false

Chemistry

2 answers:

11111nata11111 [884]3 years ago

8 0

True, bc each element emits lights that have an unique wavelength and frequency

WARRIOR [948]3 years ago

3 0

Answer:

true

Explanation:

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What is a covalent bond?

Sphinxa [80]

It is the electron sharing.
electronegative element + electronegative element

exemple :

O₂ , H₂

hope this helps!

3 0

3 years ago

Which of the following is(are) the reason(s) metals are good conductors of heat and electricity? Select all that apply

Mariana [72]

Answer: The question is incomplete and the options are not given but here are the options.

a. Metals can absorb more heat flow than other elements before damage occurs.

b. Particles of metallic structure begin to vibrate faster as they absorb energy.

c. Metals have a larger number of freely moving electrons.

d.Metals have high densities.

e. Metals have high melting points.

The correct options are c,d and e.

c. Metals have a larger number of freely moving electrons.

d.Metals have high densities.

e. Metals have high melting points.

The correct options are c,d and e.

Explanation:

Metals are real good conductor of heat because of the following;

Metals have larger number of freely moving electrons and these electrons move in random motion that is they are not stable, they from from place to place. Current generated in a direction is destroyed by current produced in another direction also.

Metals have high densities which is because their crystal lattice are packed very tight in the metallic structure making the metal bond to be stronger and conduct heat.

Metals have high melting point because that have a very strong metallic bond and this bond require a lot of energy to break, therefore making it to conduct heat and electricity.

5 0

3 years ago

Calculate ΔHo for the following reaction ussing the given bond dissociation energiesCH4(g) + 2O2(g) --> CO2(g) + 2H2O(g)BOND

Mazyrski [523]

Answer:

The ΔH° for the following reaction is -794 kJ, hence exothermic reaction,

Explanation:

$CH_4(g) + 2O_2(g)\rightarrow CO_2(g) + 2H_2O(g) ,$ ΔH° = ?

We are given with:

$\Delta H_{O-O}=142 kJ/mol$

$\Delta H_{O=O}=498 kJ/mol$

$\Delta H_{H-O}=459 kJ/mol$

$\Delta H_{C-H}=411 kJ/mol$

$\Delta H_{C-O}=358 kJ/mol$

$\Delta H_{C=O}=799 kJ/mol$

ΔH° =

(Energies required to break bonds on reactant side) - (Energies released on formation of bonds on product side)

$\Delta H^o=(1 mol\times 4\times \Delta H_{C-H}+2 mol\times 1\times \Delta H_{O=O})-(1 mol\times 2\times \Delta H_{C=O}+2 mol\times 2\times\Delta H_{H-O})$