Pomocy zadanie na jutro chemia czesc 1 str 71 zadania 48 i 49

How many moles are in 1.51 x 10^26 atoms of xenon? will mark brainlyest

zhuklara [117]

0.94Answer:

Explanation:

TO find the number of moles in a substance given its number of

entities we use the formela

7 0

3 years ago

How does the electron-cloud model describe electrons?

Sav [38]

Answer:

C. An electron has a high probability of being in certain regions.

Explanation:

In the electron cloud model, there are no electron-orbits around the nucleus but a cloud. This cloud has various densities with respect to distance from the nucleus. The most dense region of the cloud (which is the region close to the nucleus) is where electrons has the highest probability of existence.

The model explains that an electron a greater chance of being in the region closer to the nucleus. Thus, an electron has a high probability of being in certain region of the cloud about the central nucleus. And an electrostatic force exists between the nucleus and the electrons.

7 0

2 years ago

What does 3.5 degree of unsaturation tell you?

Kaylis [27]

Answer:

It means the chemical entity is a radical

Explanation:

When we talk of unsaturation, we are referring to the number of pi-bonds in a chemical entity. The alkane, alkene and alkyne organic family are used to as common examples to explain the term unsaturation.

While alkynes have 3 bonds, it must be understood that they have 2 pi bonds only and as such their degree of saturation is two.

In the case of an alkene, there is only one single pi bond and as such the degree of unsaturation is 1.

Now in this case, we have a fractional 0.5 degree of unsaturation alongside the 3 to make a total of 3.5. So what’s the issue here?

The fractional part shows that the chemical entity we are dealing with here is a radical. While the integer 3 shows that there are 3 pi-bonds, the half pi bond remaining tells us that there is a missing electron on one of the atoms involved in the chemical bonding and as such, the 1/2 extra degree of unsaturation tends to tell us this.

Kindly recall that a radical is a chemical entity within which we have at the least an unpaired electron.

5 0

3 years ago

Name two compounds in unpolluted air?

elena-14-01-66 [18.8K]

The two compounds present in unpolluted air are carbon dioxide and water. You may think that carbn dioxide is a greenhouse gas, yes it is and at the same time not. There animals in the earth that produces carbon dioxide into the atmosphere, the carbon dioxide too, is also need for plan respiration.

3 0

2 years ago

The density of water is 1 g/cm3. brent used the following method to convert 1 g/cm3 to kg/m3.

11111nata11111 [884]

Answer:

a) The wrong denominator for the equivalent fraction of kilograms to grams

b) The use of the scale factor of length rather than the scale factor of volume for the equivalent fraction of cubic centimeters to cubic meters

c) The arrival at the correct 1000 kg/m³ rather than 0.1 g/m³ based on the expression on the left of the equation

The density of water = 1 g/cm³

The given equation is presented as follows;

1 g/cm³ × 1 kg/(1000 kg) × 100 cm³/(1 m³) = 1000 kg/m³

The error in the conversion method are;

a) The conversion, 1 kg/(1,000 kg) has an error, the correct conversion is (1 kg)/1,000 g)

b) The volume conversion error, 100 cm³/(1 m³), the correct volume conversion is (100 cm)³/(1 m³) = 1,000,000 cm³/(1 m³)

c) The right of the equal to sign error; using the left side expression only, the (wrong) answer is 0.1 g/m³

The correct equation is presented as follows;

1 g/cm³ × 1 kg/(1000 g) × 1,000,000 cm³/(1 m³) = 1000 kg/m³

Explanation: hope this help.

7 0

2 years ago