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2 years ago

7. What does the mass for each element on the periodic table represent:

Chemistry

1 answer:

____ [38]2 years ago

8 0

Answer:

Explanation:

The mass number (represented by the letter A) is defined as the total number of protons and neutrons in an atom. Consider the table below, which shows data from the first six elements of the periodic table. Consider the element helium. Its atomic number is 2, so it has two protons in its nucleus.

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He (Helium) is _________ atomic molecule.

babunello [35]

Answer:

Monatomic molecule

Explanation:

Each helium atom has 2 electrons, which is already the maximum no. of electrons that can fit in the first electron shell. When the outermost electron shell is full (2 for the first layer, 8 for others), the atom is stable.

Helium atom itself is already stable, so it doesn't need to combine with another helium atom to form a molecule, hence we call it monatomic.

8 0

3 years ago

Read 2 more answers

PLEASE HELPPPP IM GIVING THE TEST RN

Tom [10]

Answer:

answer is c

Explanation:

single replacement

6 0

3 years ago

An inventor claims to have devised a closed cyclic engine which exchanges heat with cold and hot reservoirs at 25 and 350 ◦C, re

kati45 [8]

Explanation:

The given data is as follows.

$T_{c} = 25^{o}C$ , $T_{h} = 350^{o}C$

Work produced per kJ of heat extracted from hot reservoir = 0.45 kJ = Efficiency

If the device is Carnot cycle then its efficiency will be maximum and its value will be equal to $[1 - (\frac{T_{c}}{T_{h}} )]$

Using this relation we will calculate the efficiency as follows.

Efficiency = $[1 - (\frac{T_{c}}{T_{h}} )]$

= $1 - (\frac{25}{350})$

= 0.928

Hence, it means that this type of device is possible and the claim is also believable.

7 0

3 years ago

At constant pressure, how are the temperature and volume of a gas related?

RideAnS [48]

Answer:

The volume of a given gas sample is directly proportional to its absolute temperature at constant pressure (Charles's law). The volume of a given amount of gas is inversely proportional to its pressure when temperature is held constant (Boyle's law).

4 0

2 years ago

A container of gas is initially at 0.25 atm and 0 ˚C. What will the pressure be at 125 ˚C?

Pani-rosa [81]

Answer:

0.37atm

Explanation:

Given parameters:

Initial pressure = 0.25atm

Initial temperature = 0°C = 273K

Final temperature = 125°C = 125 + 273 = 398K

Unknown: