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2 years ago

NEED URGENT HELP WITH SCIENCE HOMEWORK. TRIED MY BEST TO FIGURE OUT BUT COULDNT. I WILL MARK YOU BRAINLIEST!!

Chemistry

1 answer:

Dennis_Churaev [7]2 years ago

8 0

Answer:

1. a

2. c

3. b

4. d

5. True

6. True

7. Cold Tundra

8. False

Explanation:

These are the answers. I had the same questions on my science quiz.

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scientists often look for and attempt to explain patterns in nature. explain why patterns are important

Ronch [10]

patterns are important because they prove life has meaning ( or if you mean

Scientifically is is that the ability to recognize and create patterns help scientists make predictions based on there observations.

8 0

2 years ago

1 When a chemical reaction occurs A. the substances involved do not mix together and maintain their original properties. B. the

nlexa [21]

Answer:

Explanation:

The proberties of the substances that are produced are different from the properties of the original substances.

6 0

2 years ago

PLEASE ANSWER...........WILL MARK BRAINLIEST!!!!!!!

ANTONII [103]

Answer:

<h2>The Alkali metal halide may precipitate or there may be no change at all</h2>

Explanation:

Alkali metal cations are positively charged. Halogen anions are negatively charged. When a solution of Alkali metal cations is added to a solution of Halogen anions, there are two possibilities :

The alkali metal halide( salt formed from reation of the two ions) may precipitate if the Ionic product is higher than the Solubility product.
However, if it can remain in the solution, it will remain so. No chemical changes happen with respect to these both ions. Nothing willl happen.

There is no reaction happening in either of the cases because both species are already in ionic form before addition, hence they continue to be in this form.

3 0

2 years ago

A radioactive isotope of potassium (k) has a half-life of 20 minutes. if a 43 gram sample of this isotope is allowed to decay fo

Ksenya-84 [330]

Hello!

The half-life is the time of half-disintegration, it is the time in which half of the atoms of an isotope disintegrate.

We have the following data:

mo (initial mass) = 43 g

m (final mass after time T) = ? (in g)

x (number of periods elapsed) = ?

P (Half-life) = 20 minutes

T (Elapsed time for sample reduction) = 80 minutes

Let's find the number of periods elapsed (x), let us see:

$T = x*P$

$80 = x*20$

$80 = 20\:x$

$20\:x = 80$

$x = \dfrac{80}{20}$

$\boxed{x = 4}$

Now, let's find the final mass (m) of this isotope after the elapsed time, let's see:

$m = \dfrac{m_o}{2^x}$

$m = \dfrac{43}{2^{4}}$

$m = \dfrac{43}{16}$

$\boxed{\boxed{m = 2.6875\:g}}\end{array}}\qquad\checkmark$

I Hope this helps, greetings ... DexteR! =)

8 0

2 years ago

How are half life and radioactive decay related

hoa [83]

Answer : Half life and radioactive decay are inversely proportional to each other.

Explanation :

The mathematic relationship between the half-life and radioactive decay :

$N=N_oe^{-\lambda t}$ ................(1)

where,

N = number of radioactive atoms at time, t

$N_o$ = number of radioactive atoms at the beginning when time is zero

e = Euler's constant = 2.17828

t = time

$\lambda$ = decay rate

when $t=t_{1/2}$ then the number of radioactive decay become half of the initial decay atom i.e $N=\frac{N_o}{2}$ .

Now substituting these conditions in above equation (1), we get

$\frac{N_o}{2}=N_oe^{-\lambda t_{1/2}}$

By rearranging the terms, we get

$\frac{1}{2}=e^{-\lambda t_{1/2}}$

Now taking natural log on both side,

$ln(\frac{1}{2})=-\lambda \times t_{1/2}$

By rearranging the terms, we get

$t_{1/2}=\frac{0.693}{\lambda}$

This is the relationship between the half-life and radioactive decay.

Hence, from this we conclude that the Half life and radioactive decay are inversely proportional to each other. That means faster the decay, shorter the half-life.

3 0

2 years ago