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3 years ago

What is atomic mass?

1 answer:

8 0

Atomic mass is the quantity of protons that have in a atom. Which atom have different numbers of protons, being able to be identified by them.

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During an experiment a student measured the mass of a copper wire to be

Aleksandr-060686 [28]

Quantitative data because it involves a number (quantity)

5 0

3 years ago

A hydrate is a compound that has water molecules within its crystal structure. Magnesium sulfate heptahydrate, MgSO4·7H2O, is a

Alenkasestr [34]

Answer:

We are heating the sample repeatedly to become a pure compound of only MgSO4 (withot H2O) and a constant mass.

Explanation:

Step 1: Data given

Mass of MgSO4·7H2O = 5.06 grams

The remaining MgSO4 had a constant mass of 2.47 grams.

Step 2: Explain why the sample in the crucible was heated repeatedly until the sample had a constant mass.

Before heating the compound has magnesium sulfate and water.

The total mass of this compound is 5.06 grams

By heating we try to eliminate the water.

After heating there remain mgSO4 with a mass of 2.47 grams

This means 5.06 - 2.47 = 2.59 grams is water. All of this is eliminated.

The heating process happens repeatedly to make sure the final compound is pure. So the 2.47 grams os only MgSO4. If the mass would not be constant. It means the compound is not pure, the not all the water is eliminated yet.

So we are heating the sample repeatedly to become a pure compound of only MgSO4 (withot H2O) and a constant mass.

4 0

3 years ago

The surface area of an object to be gold plated is 49.8 cm2 and the density of gold is 19.3 g/cm-3. A current of 3.15. A is appl

garik1379 [7]

Answer: Time required to deposit an even layer of gold with given thickness is $5.3 \times 10^{2}$ sec.

Explanation:

The given data is as follows.

Surface area = 49.8 $cm^{2}$ ,

Density of gold = 19.3 $g/cm^{3}$ ,

Current = 3.15 A, thickness of gold layer = $1.2 \times 10^{-3} cm$

It is known that relation between volume, area and thickness is as follows.

V = Surface area × Thickness

= $49.8 \times 1.2 \times 10^{-3} cm$

= 0.05988 $cm^{3}$

Therefore, we will calculate the time required to deposit an even layer of gold with given thickness is calculated as follows.

$0.05988 \times cm^{3} \times \frac{19.3 g Au}{1 cm^{3}} \times \frac{1 mol Au}{197 g Au} \times \frac{3 mol e^{-}}{1 mol Au} \times \frac{96485}{1 mol e^{-}} \times \frac{1 As}{1 C} \times \frac{1}{3.20 A}$

= $5.3 \times 10^{2}$ sec

Thus, we can conclude that time required to deposit an even layer of gold with given thickness is $5.3 \times 10^{2}$ sec.

4 0

3 years ago

How many electrons can be held in the second orbital (closest to the nucleus)

anzhelika [568]

A valence electron structure would be like this 1s^2 2s^2 2p^6 etc
1s^2 would be 2, 2s^2 would be 4, 2p^6 would be 12 and so on and so forth.

6 0

3 years ago

Read 2 more answers

Aqueous potassium phosphate was mixed with aqueous magnesium chloride, and a crystallized magnesium phosphate product was formed

scoray [572]

<u>Answer:</u> The other product formed is potassium chloride.

<u>Explanation:</u>

Precipitation reaction is defined as the chemical reaction in which an insoluble salt is formed when two solutions are mixed containing soluble substances. The insoluble salt settles down at the bottom of the reaction mixture.

The chemical equation for the reaction of potassium phosphate and magnesium chloride follows:

$2K_3PO_4(aq.)+3MgCl_2(aq.)\rightarrow Mg_3(PO_4)_2(s)+6KCl(aq.)$

By Stoichiometry of the reaction:

2 moles of aqueous solution of potassium phosphate reacts with 3 moles of aqueous solution of magnesium chloride to produce 1 mole of solid magnesium phosphate and 6 moles of aqueous solution of potassium chloride.

Hence, the other product formed is potassium chloride.

4 0

4 years ago