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3 years ago

Why did the toads disappear

Chemistry

1 answer:

abruzzese [7]3 years ago

7 0

Answer: extremely sensitive to environmental changes caused by habitat destruction, climate change, pollution

Explanation:

Across the world, amphibians have been disappearing at an unprecedented rate — faster than any other group of animals. Frogs, toads, and salamanders are extremely sensitive to environmental changes caused by habitat destruction, climate change, pollution, and invasive species.

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Can someone please explain core and valence electrons in periods for me please

Lena [83]

Answer:

The electrons of an atom are typically divided into two categories: valence and core electrons. Valence electrons occupy the outermost shell or highest energy level of an atom while core electrons are those occupying the innermost shell or lowest energy levels

Explanation:

i hope u get it :))

6 0

3 years ago

These diagrams show two atoms of fluorine and an atom of magnesium.

Diano4ka-milaya [45]

The magnesium atom looses two electrons which are accepted by each of the fluorine atoms. (Option D).

<h3>What is an ionic bond?</h3>

An ionic bond is formed when two ions are formed by the loss or gain electrons. In this case, magnesium has to loose two electrons while fluorine will gain two electrons.

Thus, the correct steps in the formation of an ionic bond between these atoms are A magnesium atom donates two electrons to the fluorine atoms → Each fluorine atom accepts one of the electrons → The magnesium atom becomes a +2 ion → Each fluorine atom becomes a -1 ion (Option D).

Learn more about ionic bond:brainly.com/question/11527546

#SPJ1

6 0

2 years ago

The nth shell holds a minimum number of 2n2 electrons<br> True<br> False<br> Other:

BARSIC [14]

Answer: The statement the $n^{th}$ shell holds a minimum number of $2n^{2}$ electrons is true.

Explanation:

The alphabet 'n' denotes the principal quantum number whose value can be equal to 1, 2, 3, and so on but can never be zero.

Basically, 'n' is the number of shell of an atom and total number of orbitals present in a shell is $n^{2}$ .

Each orbital can hold up to a maximum of wo electrons. Hence, the $n^{th}$ shell can hold a minimum number of $2n^{2}$ electrons.

Thus, we ca conclude that the statement the $n^{th}$ shell holds a minimum number of $2n^{2}$ electrons is true.

8 0

3 years ago

Carbon dioxide dissolves in water to form carbonic acid, which is primarily dissolved CO2. Dissolved CO2 satisfies the equilibri

lorasvet [3.4K]

Explanation:

The reaction equation will be as follows.

$CO_{2}(aq) + H_{2}O \rightleftharpoons H^{+}(aq) + HCO^{-}_{3}(aq)$

Calculate the amount of $CO_{2}$ dissolved as follows.

$CO_{2}(aq) = K_{CO_{2}} \times P_{CO_{2}}$

It is given that $K_{CO_{2}}$ = 0.032 M/atm and $P_{CO_{2}}$ = $1.9 \times 10^{-4}$ atm.

Hence, $[CO_{2}]$ will be calculated as follows.

$[CO_{2}]$ = $K_{CO_{2}} \times P_{CO_{2}}$

= $0.032 M/atm \times 1.9 \times 10^{-4}atm$

= $0.0608 \times 10^{-4}$

or, = $0.608 \times 10^{-5}$

It is given that $K_{a} = 4.46 \times 10^{-7}$

As, $K_{a} = \frac{[H^{+}]^{2}}{[CO_{2}]}$

$4.46 \times 10^{-7} = \frac{[H^{+}]^{2}}{0.608 \times 10^{-5}}$

$[H^{+}]^{2}$ = $2.71 \times 10^{-12}$

$[H^{+}]$ = $1.64 \times 10^{-6}$

Since, we know that pH = $-log [H^{+}]$

So, pH = $-log (1.64 \times 10^{-6})$

= 5.7

Therefore, we can conclude that pH of water in equilibrium with the atmosphere is 5.7.

3 0

3 years ago

If nicotine has a molar mass of 160±5g/mol , what is its molecular formula?

navik [9.2K]

Answer:

C10H14N2

Explanation:

I don't believe one can deduce the molecular formula from just it's molar mass. There are too many possible combinations of elements that could add to the same mass. This is the correct formula for nicotine, taken from known information, not from an analysis of the molar mass alone. One can confirm the molar mass is in the correct range:

C10: 10*12 = 120

H14: 14*1 = 14

N2: 2*14 = <u> 28</u>

Total = 162 which is 160±5g/mol

8 0

3 years ago