Which of the following is an example of chemical weathering?

Which property of water causes water drops to bead on a freshly waxed car?

astraxan [27]

Answer:

Cohesive forces are greater than adhesive forces

Step-by-step explanation:

The attractive forces between water molecules and the wax on a freshly-waxed car (adhesive forces) are quite weak.

However, there are strong attractive forces (cohesive forces) between water molecules.

The water molecules are only weakly attracted to the wax, so the cohesive forces pull the water molecules together to form beads .

3 0

3 years ago

Arrange the following ions in order of increasing ionic radius.

Zepler [3.9K]

Answer:

Ca 2+ <K + <Ar<Cl − <S 2−

Explanation:

Ar,K + ,Cl − ,S 2− ,Ca 2+

have the same number of electrons. Their radii would be different because of their different nuclear charges. The cation with the greater positive charge will have a smaller radius because of the greater attraction of the electrons to the nucleus. Anion with the greater negative charge will have the larger radius. In this case, the net repulsion of the electrons will outweigh the nuclear charge and the ion will expand in size. Hence the correct order will be Ca

2+ <K + <Ar<Cl − <S 2−

3 0

2 years ago

How do atoms form a new substance?

lubasha [3.4K]

By sharing electeons with each other
if they lose or gain electrons then they only form ions
they cannot lose neutrons as they are locked inside the nucleus

8 0

3 years ago

What is the energy of an electromagnetic wave with a frequency of 8•10^12 Hz?

aniked [119]

Hello!

Find the Energy of the Photon by Planck's Equation, given:

E (photon energy) =? (in Joule)

h (Planck's constant) = $6.626*10^{-34}\:J * s$

f (radiation frequency) = $8*10^{12}\:Hz$

Therefore, we have:

$E = h*f$

$E = 6.626*10^{-34}*8*10^{12}$

$E = 53.008*10^{-34+12}$

$E = 53.008*10^{-22}$

$\boxed{\boxed{E = 5.3008*10^{-21}\:Joule}}\end{array}}\qquad\checkmark$

I Hope this helps, greetings ... DexteR! =)

8 0

3 years ago

A buffer contains 0.18 mol of propionic acid (C2H5COOH) and 0.26 mol of sodium propionate (C2H5COONa) in 1.20 L. What is the pH

Yuki888 [10]

Answer:

1) pH = 5.05

2) pH = 5.13

3) pH = 4.97

Explanation:

Step 1: Data given

Number of moles of propionic acid = 0.18 moles

Number of moles sodium propionate = 0.26 moles

Volume = 1.20 L

Ka = 1.3 * 10^-5 → pKa = 4.989

Step 2: Calculate concentrations

Concentration = moles / volume

[acid]= 0.18/ 1.2 =0.150 M

[salt]= 0.26/ 1.3 = 0.217 M

pH = 4.89 + log(0.217/0.150)=<u>5.05</u>

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What is the pH of the buffer after the addition of 0.02 mol of NaOH?

moles acid = 0.18 - 0.02 = 0.16

[acid]= 0.16/ 1.2=0.133 M

moles salt = 0.26 + 0.02 = 0.28

[salt]= 0.28/ 12=0.233

pH = 4.89 + log 0.233/ 0.133 = 5.13

What is the pH of the buffer after the addition of 0.02 mol of HI?

moles acid = 0.18+ 0.02 = 0.20 moles

[acid]= 0.20/ 1.2 = 0.167 M

[salt]= 0.26 - 0.02= 0.24 moles

[salt]= 0.24/ 1.2 = 0.20 M

pH = 4.89 + log 0.20/ 0.167= 4.97

8 0

2 years ago