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3 years ago

How you find a unknown element (just with the atomic emission spectrum)

1 answer:

5 0

Each natural element has a characteristic light spectrum that helps identify it in samples of unknown substances. Spectroscopy is the practice of examining spectra and comparing them to those of known elements. Using spectroscopy methods, scientists can identify pure substances or compounds and the elements in them.

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I really need help with this question please help me.

oksano4ka [1.4K]

I would say A because it’s the only one that doesn’t conduct electricity. Ionic compounds conduct electricity, and covalent compounds do not.

3 0

3 years ago

What provides great Britan with a moderate climate

Fynjy0 [20]

The Gulf Stream affects the climate in Britain by bringing warm water from the Caribbean to North West Europe. This keeps the climate in Britain warmer than other places at a similar latitude.

3 0

2 years ago

Dry ice is solid carbon dioxide. Instead of melting, solid carbon dioxide sublimes according to the following equation: CO2(s)→C

GREYUIT [131]

Answer:

$m=8.79kg$

Explanation:

First of all we need to calculate the heat that the water in the cooler is able to release:

$Q=\rho * V*Cp*\Delta T$

Where:

Cp is the mass heat capacity of water
V is the volume
$\rho$ is the density

$Q=1 g/cm^3 *15000 cm^3*4.184 \frac{J}{g*^{\circ}C}*(10-90)^{\circ}C$

$Q=-5020800 J=-5020.8 kJ$

To calculate the mass of CO2 that sublimes:

$-Q=\Delta H_{sub}*m$

Knowing that the enthalpy of sublimation for the CO2 is: $\Delta H_{sub}=571 kJ/kg$

$5020.8 kJ=571 kJ/kg*m$

$m=\frac{5020.8 kJ}{571 kJ/kg}=8.79kg$

6 0

3 years ago

Score:

pishuonlain [190]

Some of the NH₄+ will combine with the OH- and shift the equilibrium backwards and from NH₄OH to balance the change produced by addition of NH₄+ ions.

5 0

3 years ago

A balloon contains 2.0 L of air at 101.5 kPa . You squeeze the balloon to a volume of 0.25 L.

8_murik_8 [283]

<h3>Answer:</h3>

812 kPa

<h3>Explanation:</h3>

According to Boyle's law pressure and volume of a fixed mass are inversely proportional at constant absolute temperature.

Mathematically, $P\alpha \frac{1}{V}$

At varying pressure and volume;

P1V1=P2V2

In this case;

Initial volume, V1 = 2.0 L

Initial pressure, P1 = 101.5 kPa

Final volume, V1 = 0.25 L

We are required to determine the new pressure;

$P2=\frac{P1V1}{V2}$

Replacing the known variables with the values;

$P2=\frac{(101.5)(2.0L)}{0.25L}$

= 812 kPa

Thus, the pressure of air inside the balloon after squeezing is 812 kPa

8 0

3 years ago