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3 years ago

BRAINLIESTT ASAP! PLEASE HELP :)

Chemistry

1 answer:

DanielleElmas [232]3 years ago

6 0

Answer:

The change during the burning of a match stick is a irreversible chemical change while the change when a liquid starts boiling is reversible chemical change.

You Helped Me Lol

Explanation:

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How does evaporation lead to precipitation

Serhud [2]

Answer:

1.evaperation

2.condenstation

3.precipatation

Explanation:

So I guess condenstation leads to precipatation-

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3 years ago

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The coolest stars in the sky are ____ in color

Mekhanik [1.2K]

Red is the answer in the blank

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3 years ago

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You have just isolated a new radioactive element. If you can determine its half-life, you will win the Nobel Prize in physics. Y

lbvjy [14]

Answer: 2.58 days

Explanation:

Expression for rate law for first order kinetics is given by:

$t=\frac{2.303}{k}\log\frac{a}{a-x}$

where,

k = rate constant = ?

t = age of sample = 6 days

a = initial amount of the reactant = 1 g

a - x = amount left after decay process = 0.2 g

a) to find the rate constant

$6=\frac{2.303}{k}\log\frac{1.0}{0.2}$

$k=\frac{2.303}{6}\log\frac{1.0}{0.2}$

$k=0.268days^{-1}$

b) for completion of half life:

Half life is the amount of time taken by a radioactive material to decay to half of its original value.

$t_{\frac{1}{2}}=\frac{0.693}{k}$

$t_{\frac{1}{2}}=\frac{0.693}{0.268}=2.58days$

The half life is 2.58 days

3 0

3 years ago

the temperature of a sample of water increases from 20celsius to 46.6celsius as it absorbs 5650 J of heat. what is the mass of t

Levart [38]

Answer:

m = 50.74 kg

Explanation:

We have,

Initial temperature of water is 20 degrees Celsius

Final temperature of water is 46.6 degrees Celsius

Heat absorbed is 5650 J

It is required to find the mass of the sample. The heat absorbed is given by the formula ad follows :

$Q=mc\Delta T$

c is specific heat of water, c = 4.186 J/g°C

So,

$m=\dfrac{Q}{c\Delta T}\\\\m=\dfrac{5650}{4.186\times (46.6-20)}\\\\m=50.74\ kg$

So, the mass of the sample is 50.74 kg.

8 0

3 years ago

How many solutions does the equation (3x + 7) = -4 have?<br>B. one<br>C. WO<br>D. infinitely many

Eddi Din [679]

Answer:

Its One

Explanation:

hope it helps!

mark me brainliest :))

8 0

4 years ago