3 years ago

Study the timeline.

Chemistry

2 answers:

Eddi Din [679]3 years ago

6 0

Answer:

4.1 billion years ago

Explanation:

kherson [118]3 years ago

3 0

4.1 billion years ago.

You might be interested in

What do all atoms in a period (horizontal rows) have in common?

scoray [572]

Answer:

the same number of atomic orbitals.

Explanation:

5 0

2 years ago

Read 2 more answers

How many moles are in 7.2 x 10^23 carbon molecules?

choli [55]

Explanation:

It is known that in 1 mole there are $6.023 \times 10^{23}$ atoms or molecules.

It is given that there are $7.2 \times 10^{23}$ carbon molecules. Therefore, calculate the moles as follows.

Number of moles = $\frac{7.2 \times 10^{23} molecules}{6.023 \times 10^{23} molecules/mol}$

= 1.196 mol

Thus, we can conclude that there are 1.196 mol in $7.2 \times 10^{23}$ carbon molecules.

7 0

3 years ago

Several teeth were found in an area of flat land covered with trees and plants. The teeth were examined by a paleontologist, and

djverab [1.8K]

B because that makes the most sense

3 0

3 years ago

Read 2 more answers

Is potassium iodide an electrolyte or nonelectrolyte?

Lera25 [3.4K]

Its a strong electrolyte!.

6 0

4 years ago

What is the half-life of an isotope that decays to 12.5% of its original activity in 19.8 hours?

katen-ka-za [31]

$x= x_{0} e^{kt} ,where~ x ~is~ the ~ |amount\ of \material\ at\ any~~time~t
$
$and~ x_{0} ~the~original~amount.$
$when~x= \frac{12.5}{100} x_{0} }= \frac{125}{1000} x_{0}$
$\frac{x}{ x_{0} } = \frac{125}{1000}= \frac{1}{8}$
$when t=19.8 hrs,
x= x_{0} e^{19.8 k}, 
 \frac{x}{ x_{0} } = e^{19.8 k}, 
 \frac{1}{8} = e^{19.8k} ,
ln \frac{1}{8} =19.8 k,
$
$ln1-ln8=19.8k,
0-ln 2^{3} =19.8 k,
-3 ln2=19.8k
k= \frac{-3 ln2}{19.8} = \frac{- ln 2}{6.6}$ $x= x_{0} e^{ \frac{-ln2}{6.6}t } ,
 \frac{x}{ x_{0} } = e^{ \frac{- ln 2}{6.6}t } 
$ $\frac{1}{2} = e^{ \frac{- ln2}{6.6}t } = \frac{1}{ e^{ \frac{ln 2}{6.6} t} } ,
2= e^{ \frac{ln2}{6.6}t } ,
ln2=ln e^{ \frac{ln 2}{6.6}t } = \frac{ln 2}{6.6} t~ln e= \frac{ln2}{6.6} t,$

8 0

4 years ago