Which atom in the O-F bond has a partial positive charge (δ⁺)?

Pleaseeeeeee hlepThe half-life of cobalt-60 is 5.26 years. After 10.52 years, 5 grams of a 20-gram sample will remain.

vladimir1956 [14]

The half-life of cobalt-60 is 5.26 years. After 10.52 years, 5 grams of a 20-gram sample will remain is TRUE

<u>Explanation:</u>

Mass of cobalt = 20 g

Half-life = 5.26 years

Mass remains after 10.52 years = 5 g

This can be solved by using given below formula, $m(t)=m_{o}\left(\frac{1}{2}\right)^{\frac{l}{5.26}}$

$m_{0}$ = initial mass

t = number of years from when the mass was m_0

m(t) = remaining mass after t years

Number of half-lives = $\frac{\text { Time elapsed }}{\text { Half -life }}$

Number of half-lives = $\frac{10.52 \text { years }}{5.26 \text { years }}$

Number of half-lives = 2

At time zero = 20 g

At first half-life = $\frac{20\ g}{2}$ = 10 g

At second half life = $\frac{10\g}{2}$ = 5 g

The given statement is true.

4 0

3 years ago

What will be the the net ionic equations for the following ones:- a) AgNO3 + KCl b) Ni(NO3)2 + Na2S c) CaCl2 + Na2CO3. 2) Write

Zielflug [23.3K]

In a) the final equation is AgNO3 + KCl = AgCl + KNO3, b) Ni(NO3)2 + Na2S = 2NaNO3 + NiS; c) CaCl2 + Na2CO3 = 2 NaCl + CaCO3. In 2) The total net equation is Ca 2+ + CO32- = CaCO3 (s).

4 0

3 years ago

The half-life of carbon-14 is 5,730 years. How many grams of parent material will remain from a 200-gram sample after 3 half-liv

Alex17521 [72]

Answer:

The answer to your question is 25 grams

Explanation:

Data

half-life = 5730 years

sample = 200 g

after 3 half-lives

Process

Calculate the amount of sample after one, two and three half-lives.

After each half-life, that of sample is half the previous amount.

Number of half-lives Amount of sample

0 200 g

1 100 g

2 50 g

3 25 g

4 0

3 years ago

In which way would a drought affect how rodents get their energy?

love history [14]

Answer:

<h3>When a drought occurs, their food supply can shrink and their habitat can be damaged. ... Losses or destruction of fish and wildlife habitat. Lack of food and drinking water for wild animals. Increase in disease in wild animals, because of reduced food and water supplies.</h3><h3>While insects and cacti might provide a meagre supply of water, most desert animals survive by being what Price calls "water misers". ... To perform this feat, they have evolved specialized kidneys with extra microscopic tubules for extracting water from urine.</h3>

Explanation:

3 0

3 years ago

Write Lewis structures for the following molecules: (a) ICl, (b) PH3, (c) P4 (each P is bonded to three other P atoms), (d) H2S,

spin [16.1K]

Answer : The Lewis-dot structure for the following molecules are shown below.

Explanation :

Lewis-dot structure : It shows the bonding between the atoms of a molecule and it also shows the unpaired electrons present in the molecule.

In the Lewis-dot structure the valance electrons are shown by 'dot'.

Now we have to determine the Lewis-dot structure for the following molecules.

(a) The given molecule is, $ICl$

As we know that iodine and chlorine have '7' valence electrons.

Therefore, the total number of valence electrons in $ICl$ = 7 + 7 = 14

According to Lewis-dot structure, there are 2 number of bonding electrons and 12 number of non-bonding electrons.

(b) The given molecule is, $PH_3$

As we know that phosphorous has '5' valence electrons and hydrogen has '1' valence electrons.

Therefore, the total number of valence electrons in $PH_3$ = 5 + 3(1) = 8

According to Lewis-dot structure, there are 6 number of bonding electrons and 2 number of non-bonding electrons.

(c) The given molecule is, $P_4$

As we know that phosphorous has '5' valence electrons.

Therefore, the total number of valence electrons in $P_4$ = 4(5) = 20

According to Lewis-dot structure, there are 6 number of bonding electrons and 14 number of non-bonding electrons.

(d) The given molecule is, $H_2S$

As we know that sulfur has '6' valence electrons and hydrogen has '1' valence electrons.

Therefore, the total number of valence electrons in $H_2S$ = 6 + 2(1) = 8

According to Lewis-dot structure, there are 4 number of bonding electrons and 4 number of non-bonding electrons.

(e) The given molecule is, $N_2H_4$

As we know that nitrogen has '5' valence electrons and hydrogen has '1' valence electrons.

Therefore, the total number of valence electrons in $N_2H_4$ = 2(5) + 4(1) = 14

According to Lewis-dot structure, there are 10 number of bonding electrons and 4 number of non-bonding electrons.

(f) The given molecule is, $HClO_3$

As we know that chlorine has '7' valence electrons, oxygen has '6' valence electrons and hydrogen has '1' valence electrons.

Therefore, the total number of valence electrons in $HClO_3$ = 1 + 7 + 3(6) = 26

According to Lewis-dot structure, there are 12 number of bonding electrons and 14 number of non-bonding electrons.

(g) The given molecule is, $COBr_2$

As we know that bromine has '7' valence electrons, oxygen has '6' valence electrons and carbon has '4' valence electrons.

Therefore, the total number of valence electrons in $COBr_2$ = 4 + 6 + 2(7) = 24

According to Lewis-dot structure, there are 8 number of bonding electrons and 16 number of non-bonding electrons.

3 0

3 years ago