Are protons and neutrons the same size? Explain.

Silicon has 2 isotopes, Silicon-28 with an abundance of 90% and Silicon-30 with an abundance of 10%. Find the AAM for Silicon.

JulsSmile [24]

Answer:

RAM

$RAM = (mass \: of \: ^{28} Si \: \times \%abundance) + (mass \: of \: ^{30} Si \: \times \%abundance) \\ RAM = (28 \times 90\%) + (30 \times 10\%) \\ RAM = 25.2 + 3 \\ RAM = 28.2$

5 0

3 years ago

John dissolves .5g of a white powder in 25g of benzene (FP 5oC) (kf benzene is 5.1) and finds the solution freezes at 3.7oC. Det

navik [9.2K]

Answer:

The compound has a molar mass of 78.4 g/mol

Explanation:

Step 1: data given

Mass of a sample = 0.5 grams

Mass of benzene = 25 grams

Freezing poing = 5 °C

Kf of benzene = 5.1 °C/m

Freezing point solution = 3.7 °C

Step 2: Calculate molality

ΔT = i*Kf*m

⇒with ΔT = the freezing point depression = 5.0 - 3.7 = 1.3 °C

⇒with i = the can't hoff factor = 1

⇒with Kf = the freezing point depression constant of benzene = 5.1 °C/m

⇒with m = the molality

1.3 = 5.1 * m

m = 1.3 / 5.1

m = 0.255 moles /kg

Step 3: Calculate moles

Molality = moles / mass benzene

0.255 molal = moles / 0.025 kg

Moles = 0.255 molal * 0.025 kg

Moles = 0.006375 moles

Step 4: Calculate molar mass of the compound

Molar mass compund = mass / moles

Molar mass compound = 0.5 grams / 0.006375 moles

Molar mass compound = 78.4 g/mol

The compound has a molar mass of 78.4 g/mol

7 0

3 years ago

Under standard-state conditions, which of the following half-reactions occurs at the cathode during the electrolysis of aqueous

Slav-nsk [51]

Answer:

The following reaction will occur at cathode:

$Ni^{+2}(aq)+2e--->Ni(s)$

Explanation:

The two half reaction during electrolysis of aqueous nickel sulfate will be

a) anode reaction :

Water will undergo oxidation and will evolve oxygen gas at anode as shown in the given reaction:

$2H_{2}O(l) ----> O_{2}(g) + 4H^{+}(aq) + 4e$

b) Cathode reaction: The reduction of Nickel ion will occur by gain of two electrons as shown in the given equation:

$Ni^{+2}(aq)+2e--->Ni(s)$

Thus the overall reaction will be:

$2H_{2}O(l) + 2Ni^{+2}----> O_{2}(g) + 4H^{+}(aq) + 2Ni(s)$

6 0

3 years ago

An extra-strength aspirin contains 0.500 g of aspirin. how many grains is this? (1grain=64.8mg)

Snowcat [4.5K]

By unit conversion, the aspirin contains 7.72 grains.

We need to know about unit conversion to solve this problem. The unit conversion can be used to convert a unit to another unit. It can be defined as

a = xb

where a is unit a, b is unit b and x is the constant of conversion.

From the question above, we know that

m = 0.5 gram

unit conversion

(1 grain = 64.8 mg)

Convert the unit conversion to 1 mg

1 grain = 64.8 mg

1/64.8 grain = 64.8/64.8 mg

1 mg = 1/64.8 grain

Convert the aspirin mass to grain

m = 0.500 g

m = 0.5 x 10³ mg

m = 0.5 x 10³ x 1/64.8 grain

m = 7.72 grain

Find more on unit conversion at: brainly.com/question/4158962

#SPJ4

8 0

1 year ago

Explain how CO2 is absorbed into the ocean of H2O

Dmitrij [34]

The ocean absorbs CO2 from the atmosphere wherever air meets water. Wind causes waves, giving more opportunity for the water to absorb the carbon dioxide.

7 0

3 years ago