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3 years ago

Land is a natural resource because it is used by living things to meet their needs. O True

Chemistry

1 answer:

blondinia [14]3 years ago

7 0

Answer:

Absolutely True :) cause we use it all the time

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3. Why do you think the image of the pencil inside the beaker of water is different than the pencil

tia_tia [17]

Answer:

the water.

Explanation:

well the water makes things look larger than due to ( the surface of a water drop curves outwards to make a dome. this outward or convex, curature light rays inward. the result is an enlarge ment image on the eye. / makes it look larger) + more mass.

6 0

3 years ago

PLEASE HELP this is physical science.

Andru [333]

Bone age : 22,920 years

<h3>Further explanation</h3>

Given

Nt = 2.5 g C-14

No = 40 g

half-life = 5730 years

Required

time of decay

Solution

General formulas used in decay:

$\large{\boxed{\bold{N_t=N_0(\dfrac{1}{2})^{t/t\frac{1}{2} }}}$

t = duration of decay

t 1/2 = half-life

N₀ = the number of initial radioactive atoms

Nt = the number of radioactive atoms left after decaying during T time

Input the value :

$\tt 2.5=40.\dfrac{1}{2}^{t/5730}\\\\\dfrac{2.5}{40}=\dfrac{1}{2}^{t/5730}\\\\(\dfrac{1}{2})^4=\dfrac{1}{2}^{t/5730}\\\\4=t/5730\rightarrow t=22920~years$

6 0

2 years ago

Fix the formula for KF2<br> Write out the full correct formula?

Korvikt [17]

Given :

A chemical compound $KF_2$ .

To Find :

Fix the formula for $KF_2$ and write the full correct formula.

Solution :

We know, Potassium( K ) and Fluorine( F ) both have a valency of 1 i.e potassium can donate one electron and Fluorine can accept one electron only.

So, the chemical formula $KF_2$ is wrong because no element has filled electron.

Therefore, to stabilise the molecule, 1 Potassium atom should make a bond from 1 Fluorine i.e KF ( correct formula ) .

Hence, this is the required solution.

7 0

2 years ago

Identify the Lewis acid and Lewis base from among the reactants in each of the following equations.

Alex

Answer:

Part A

Ag+ is the Lewis acid and NH3 is the Lewis base.

Part B

AlBr3 is the Lewis acid and NH3 is the Lewis base.

Part C

AlCl3 is the Lewis acid and Cl− is the Lewis base.

Explanation:

A Lewis acid is any specie that accepts a lone pair of electrons. Ag^+, AlBr3 and AlCl3 all accepted lone pairs of electrons according to the three chemical reaction equations shown. Hence, they are Lewis acids.

A Lewis base donates a lone pair of electrons. They include neutral molecules having lone pair of electrons such as NH3 or negative ions such as Cl- .

3 0

2 years ago

Read the passage below and choose the best answer for the main idea of the passage:

Crank

Answer: C

Explanation:

4 0

2 years ago