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Rainbow [258]
3 years ago
8

In what era did reptiles become increasingly dominant?

Chemistry
2 answers:
emmainna [20.7K]3 years ago
6 0
Correct answer: B. Paleozoic. I took the test and it was right.

Leni [432]3 years ago
5 0
Palezoic I took the test!!
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a cube of iron (cp = 0.450 j/g•°c) with a mass of 55.8 g is heated from 25.0°c to 49.0°c. how much heat is required for this pro
krek1111 [17]
Q = ?

Cp = 0.450 j/g°C

Δt =  49.0ºC - 25ºC => 24ºC

m = 55.8 g

Q = m x Cp x Δt

Q = 55.8 x 0.450 x 24

Q = 602.64 J

hope this helps! 
7 0
3 years ago
Read 2 more answers
NH₄NO₃ → N₂O + 2H₂O When 45.70 g of NH₄NO₃ decomposes, what mass of each product is formed?
Anna007 [38]

Answer: 25.13 g of N_2O  and 20.56 g of H_2O will be produced from 45.70 g of NH_4NO_3

Explanation:

To calculate the moles :

\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}    

\text{Moles of} NH_4NO_3=\frac{45.70g}{80.04g/mol}=0.571moles

The balanced chemical equation is:

NH_4NO_3\rightarrow N_2O+2H_2O  

According to stoichiometry :

1 mole of NH_4NO_3 produce = 1 mole of N_2O

Thus 0.571 moles of NH_4NO_3 will require=\frac{1}{1}\times 0.571=0.571moles  of N_2O  

Mass of N_2O=moles\times {\text {Molar mass}}=0.571moles\times 44.01g/mol=25.13g

1 mole of NH_4NO_3 produce = 2 moles of H_2O

Thus 0.571 moles of NH_4NO_3 will require=\frac{2}{1}\times 0.571=1.142moles  of H_2O  

Mass of H_2O=moles\times {\text {Molar mass}}=1.142moles\times 18g/mol=20.56g

Thus 25.13 g of N_2O  and 20.56 g of H_2O will be produced from 45.70 g of NH_4NO_3

5 0
3 years ago
When a compound containing cesium ions is heated in a Bunsen burner flame, photons with an energy of 4.30 x 10-19 J are emitted.
inessss [21]

<u>Answer:</u> The wavelength of the flame is 462 nm and color of cesium flame is blue.

<u>Explanation:</u>

To calculate the wavelength, we use Planck's equation, which is:

E=\frac{hc}{\lambda}

where,

E = Energy of 1 photon = 4.30\times 10^{-19}J

h = Planck's constant = 6.625\times 10^{-34}J.s

c = speed of light = 3\times 10^8m/s

\lambda = wavelength = ?

Putting values in above equation, we get:

4.30\times 10^{-19}=\frac{6.625\times 10^{-34}J.s\times 3\times 10^8m/s}{\lambda }\\\\\lambda=\frac{6.625\times 10^{-34}J.s\times 3\times 10^8m/s}{4.30\times 10^{-19}}=4.62\times 10^{-7}m=462nm

The range of wavelength of blue light lies in range of 500 nm - 435 nm

The calculated wavelength lies in the above range. So, the color of the cesium flame is 462 nm

Hence, the wavelength of the flame is 462 nm and color of cesium flame is blue.

6 0
3 years ago
Temperature depends on the average kinetic energy of athe particles in a sample how does this help with explaining why a plasma
Kryger [21]
Most particles in the plasma are heavy and slow and this statement explains why a plasma based light does not have a high temperature. The correct option among all the options that are given in the question is the third option. It is a fact that a heavy nuclei always takes more time to reach a thermal equilibrium. 

4 0
3 years ago
Read 2 more answers
Plz I need help with my chemistry homework jJnsjs​
professor190 [17]

answer

1.1 Carbon is the sixth element in the periodic table.

(IV A)

1.2 electric configuration: O⁸ (He²) 2s² 2p⁴ .

atomic number: 8

1.3 protons= 8 , electron = 7

1.4 oxygen has 6 valence electrons .

carbon has 4 valence electrons.

1.5 the answer is in the photo.

3 0
3 years ago
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