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AnnZ [28]
3 years ago
5

PLEASE I'M OFFERING 20 POINTS AND WILL MARK BRAINLIEST. Think about how the geologic time scale was created and how it is divide

d. Then answer the following questions. How did scientists form the geologic time scale? How is this scale organized? What processes changed the Earth's environment during Precambrian time?
Chemistry
2 answers:
ioda3 years ago
5 0

Answer: (written in paragraph form)

Scientists formed the geologic time scale by looking and studying layers of rock as well as index layers from around the world. Then they decided the rocks order from the estimated date of age. The geologic scale is organized in to parts based off of important things/changes in the geologic record. This parts can be identified by the names Eras, Eons, Periods, or Ages. Eons are the biggest, having millions of years with in them. Finally, in the precambrian time, processes/results of these processes include differing climate conditions, less water erosions, and lastly photosynthesis changed the Earth's environment.

Hope this helps!  >-<

xxTIMURxx [149]3 years ago
4 0

Answer:

The geologist time scale was formed when scientists studied rock layers and index fossils worldwide. With this information, they placed Earth's rocks in order by relative age. Later, radioactive dating helped determine the exact age of the divisons in the geologic time scale.

This scale is organized by the 4.6 billion years of earth's history into sections based on important changes seen in the geologic record. The largest intervals are called eons, with each eon containing many millions of years.

In precambarian time the processes that affect Earth's surface have lessened the erosion on the surface. Earth was being hit by meteorites every second. Now there is water erosion and there wasn't back then. The surface changes have lessened over time.

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During the age of the dinosaurs, most mammals grew no bigger than a?
lianna [129]

Answer:

T-rex

Explanation:

7 0
3 years ago
What is the name of the hybrid orbitals used by sulfur in scl2? express your answer in condensed form in order of increasing orb
Marianna [84]

Answer:

sp³

Explanation:

The Lewis structure of SCl₂ is shown below.

The central S atom has two lone pairs and two bonding pairs, for four electron groups.

VSEPR theory predicts that the electron geometry is <em>tetrahedral</em>.

This corresponds to the use of sp³ hybrid orbitals.

7 0
4 years ago
t 745 K, the reaction below has an equilibrium constant (Kc) of 5.00 × 102. H2 (g) + I2 (g) ⇌ 2 HI (g) If a mixture of 0.10 mol
spayn [35]

Answer : The concentration of HI (g) at equilibrium is, 0.643 M

Explanation :

The given chemical reaction is:

                        H_2(g)+I_2(g)\rightarrow 2HI(g)

Initial conc.    0.10        0.10      0.50

At eqm.        (0.10-x)  (0.10-x)   (0.50+2x)

As we are given:

K_c=5.00\times 10^2

The expression for equilibrium constant is:

K_c=\frac{[HI]^2}{[H_2][I_2]}

Now put all the given values in this expression, we get:

5.00\times 10^2=\frac{(0.50+2x)^2}{(0.10-x)\times (0.10-x)}

x = 0.0713  and x = 0.134

We are neglecting value of x = 0.134 because the equilibrium concentration can not be more than initial concentration.

Thus, we are taking value of x = 0.0713

The concentration of HI (g) at equilibrium = (0.50+2x) = [0.50+2(0.0713)] = 0.643 M

Thus, the concentration of HI (g) at equilibrium is, 0.643 M

8 0
4 years ago
I need help finding out what this is please help
kari74 [83]

Answer:

search the Lewis dot structure you will know the answer.

4 0
3 years ago
Magnesium burns in air with a dazzling brilliance to produce magnesium oxide: 2 Mg(s) + O2(g) → 2 MgO(s) How many moles of O2 ar
TEA [102]

Answer:

1.05 mols of O2 gas

Explanation:

For this type of problem, it's important to understand what the balanced Chemical equation tells us:

<h3><u>Balanced Chemical equations</u></h3>

Let's look at the balanced chemical equation:

2Mg(s)+O_2(g)-- > 2MgO(s)

This equation two sides of the reaction arrow.  On the left are the reactants (things you start with, and that react during the chemical reaction), and on the right side are products (things that are produced during the chemical reaction that you end with).

The numbers in front of each compound tell how many of molecules are involved for a full reaction without anything left over.  A "mol" is a large quantity (6.022*10^{23}), in this case, of molecules , since it's unlikely you're only taking a single molecule of each substance (it would be so tiny, you wouldn't even know you were doing the reaction).

So,for every 2 moles of Magnesium used, we'll also need 1 mole of Oxygen, and it will produce 2 moles of Magnesium Oxide.

In a way, during the reaction it's almost like 2 moles of Magnesium is equal to 1 mole of Oxygen and is equal to 2 moles of Magnesium Oxide:

2 mol Mg(s)=1mol O_2(g)=2molMgO(s)

From here, we can build some unit ratios, to convert between the known quantity of moles we have, and find the unknown quantity of moles that are requested.

<h3><u>Finding the right unit ratio</u></h3>

We know that we are looking at 2.10 mol of Magnesium, so we want a unit ratio with moles of Mg on the bottom.  <u>We want to find moles of O2</u>, <u>so we want a unit ratio of moles of O2 on top</u>.

The unit ratio we want is the middle part of the equation, divided by the left part of the equation.

2 mol Mg(s)=1mol O_2(g)\\\frac{2 mol Mg(s)}{2 mol Mg(s)}=\frac{1mol O_2(g)}{2 mol Mg(s)}\\1=\frac{1mol O_2(g)}{2 mol Mg(s)}

Since this quantity is 1, it is a unit ratio and can be multiplied to other things to change their units (for this problem).

<h3><u>Finding the answer</u></h3>

Starting with what we know, and multiplying by our unit ratio:

2.10 mol Mg(s)*\frac{1mol O_2(g)}{2 mol Mg(s)}=1.05mol O_2(g)

Notice that the units from the first quantity cancel with the units on the bottom of the fraction, leaving only the unit on top of the fraction ... the exact units we wanted!

So, 1.05mols of O2 would be consumed during the reaction if exactly 2.10moles of Magnesium are burned.

4 0
3 years ago
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