A Is an ecosystem that is covered with water for at least part of the year

8. Which of the following statements about noble gases is correct?

Tanya [424]

Answer:

C.

Explanation:

Noble gases are stable and already have a full outter shell therefore don't tend to lose or gain any electrons.

8 0

3 years ago

Elements with atomic numbers 7 and 83 have how many valence electrons? *

IRINA_888 [86]

Explanation:

element with atomic numbers 7 and 83 have 5 and 5 valence electrons

5 0

3 years ago

Evaluate the Lewis structures below and pick the statements that best describes the accuracy of each of the structures. There ma

Artyom0805 [142]

Answer:

The structures shown by dots and lines to give the exact number of electrons in the outer most shell is explained by Lewis Structures.

Explanation:

Lewis structures are those structures in which the diagram is shown using the electron representation. They are easy to understand as the diagram completely depicts where the electrons are shared and where they are transferred. The diagram also explains where there is a single bond and where there is a di covalent bond or tri covalent bond explaining where the single , double or triple electron pair is shared. The electrons are shown by dots or lines.

For example CCl₄ can be shown as follows

..

.. Cl..

.. ..

..Cl..----------C----------..Cl..

..

.. Cl..

The picture shows that each chlorine has six electrons in its outer shell and then a pair of electron is shared with carbon forming a single covalent bond.

Similarly methane CH4 can also be shown.

The hydrogen has one electron and it shares an electron from carbon stabilising itself forming methane.

6 0

3 years ago

Which of the following has the lowest entropy?

Valentin [98]

I believe that the answer is B: H2O(s) because is the makeup of water also known as one hydrogen and two oxygen. So water as more entropy and the s stands for sol fore i think wich means it contains the most entropy.

5 0

3 years ago

Read 2 more answers

What is the mass of a sample of metal that is heated from 58.8°C to 88.9°C with a

Vadim26 [7]

Answer:

$\boxed {\boxed {\sf 333 \ grams}}$

Explanation:

We are asked to find the mass of a sample of metal. We are given temperatures, specific heat, and joules of heat, so we will use the following formula.

$Q= mc \Delta T$

The heat added is 4500.0 Joules. The mass of the sample is unknown. The specific heat is 0.4494 Joules per gram degree Celsius. The difference in temperature is found by subtracting the initial temperature from the final temperature.

ΔT= final temperature - initial temperature

The sample was heated <em>from </em> 58.8 degrees Celsius to 88.9 degrees Celsius.

ΔT= 88.9 °C - 58.8 °C = 30.1 °C

Now we know three variables:

Q= 4500.0 J
c= 0.4494 J/g°C
ΔT = 30.1 °C

Substitute these values into the formula.

$4500.0 \ J = m (0.4494 \ J/g \textdegree C)(30.1 \textdegree C)$

Multiply on the right side of the equation. The units of degrees Celsius cancel.

$4500.0 \ J = m (13.52694 J/g)$

We are solving for the mass, so we must isolate the variable m. It is being multiplied by 13.52694 Joules per gram. The inverse operation of multiplication is division, so we divide both sides by 13.52694 J/g

$\frac {4500.0 \ J }{13.52694 J/g}= \frac{m (13.52694 J/g)}{13.52694 J/g}$

The units of Joules cancel.

$\frac {4500.0 \ J }{13.52694 J/g}= m$

$332.6694729 \ g =m$

The original measurements have 5,4, and 3 significant figures. Our answer must have the least number or 3. For the number we found, that is the ones place. The 6 in the tenth place tells us to round the 2 up to a 3.

$333 \ g \approx m$

The mass of the sample of metal is approximately <u>333 grams.</u>

8 0

2 years ago