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3 years ago

I need 2 examples of chemical and physical change. *15 points

1 answer:

3 0

*Chemical: Burning of paper and log of wood. - Digestion of food. - Boiling an egg. - Chemical battery usage. - Electroplating a metal. - Baking a cake. - Milk going sour.

*Physical: An ice cube melting into water in your drink. - Freezing water to make ice cubes. - Boiling water evaporating. - Hot shower water turning to steam. - Steam from the shower condensing on a mirror.

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Examples of light effecting chemical change

Annette [7]

Answer:

burning of wood ,cooking an egg,baking a cake,rusting of iron,digestion of food .

8 0

2 years ago

In need of help very soon please.

NemiM [27]

Answer:

hello, i hope this helps.

Explanation:

1 - group

2 - period

3 - periodic table

4 - family

5 - octet rule

6 - valence electrons

6 0

2 years ago

A. Describe the molecule chlorine dioxide, CIO in terms of three possible resonance structures.

cupoosta [38]

Answer:

See explanation

Explanation:

The compound ClO2 has 19 valence electrons. ClO2 is a bent molecule with tetrahedral electron pair geometry but has two lone pairs of electrons. This is indicated by the presence of four electron pairs on the outermost shell of the central atom.

The molecule has an odd number of valence electrons, hence, it is generally regarded as a paramagnetic radical. None of the proposed Lewis structures for the molecule is satisfactory because none of them obeys the octet rule.

From the images attached, one can easily see that the electron dots around the oxygen and chlorine atoms does not satisfy the octet rule in all the resonance structures shown.

5 0

3 years ago

10 To become positively charged, an atom must: A Galn a proton B Lose a proton C С. Galn an electron D Lose an electron }

Studentka2010 [4]

Answer:

D: lose an electron

Explanation:

when an atom loses an electron it's positively charged and when it gain an electron it is negatively charged

6 0

3 years ago

A sample of gas (1.9 mol) is in a flask at 21 °C and 697 mm Hg. The flask is opened and more gas is added to the flask. The new

Artyom0805 [142]

Answer: There are now 2.07 moles of gas in the flask.

Explanation:

$PV=nRT$

P= Pressure of the gas = 697 mmHg = 0.92 atm (760 mmHg= 1 atm)

V= Volume of gas = volume of container = ?

n = number of moles = 1.9

T = Temperature of the gas = 21°C=(21+273)K= 294 K (0°C = 273 K)

R= Value of gas constant = 0.0821 Latm\K mol

$V=\frac{nRT}{P}=\frac{1.9\times 0.0821 \times 294}{0.92}=49.8L$

When more gas is added to the flask. The new pressure is 775 mm Hg and the temperature is now 26 °C, but the volume remains same.Thus again using ideal gas equation to find number of moles.

$PV=nRT$

P= Pressure of the gas = 775 mmHg = 1.02 atm (760 mmHg= 1 atm)

V= Volume of gas = volume of container = 49.8 L

n = number of moles = ?

T = Temperature of the gas = 26°C=(26+273)K= 299 K (0°C = 273 K)

R= Value of gas constant = 0.0821 Latm\K mol

$n=\frac{PV}{RT}=\frac{1.02\times 49.8}{0.0821\times 299}=2.07moles$

Thus the now the container contains 2.07 moles.

6 0

2 years ago