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miss Akunina [59]
3 years ago
7

1. According to the fossil record, the first LAND plants were most likely pine trees. moss and ferns. flowering plants. 2. Scien

tists have found fossils of pine cones, seeds, and leaves with veins. More than likely scientists would also find fossilized remains of fish. dinosaurs. mammals 3. Lots of shell fossils and no plant fossils tell us that Earth probably mostly covered with oceans and little dry land. true
Chemistry
2 answers:
Lynna [10]3 years ago
7 0

Answer:

It is true that earth was once covered with oceans and little dry land.

Explanation:

Over the course of around four billion years, the Earth's oceans have lost about a quarter of their original mass. Today the atmosphere is rich in oxygen, which reacts with both hydrogen and deuterium to recreate water, which falls back to the Earth's surface. So the vast bulk of the water on Earth is held in a closed system that prevents the planet from gradually drying out. According to the researchers,  the continents emerged relatively suddenly from an ocean that covered 95 percent of the Earth's surface. The appearance of large masses of dry land would have caused more extreme weather, changes in ocean currents and the emergence of proper seasons. In turn, these environmental changes may have led to rise in atmospheric oxygen that enabled the explosion of new life forms around 500 million years ago.

Law Incorporation [45]3 years ago
3 0

Answer:

Explanation:

`1. Moss and ferns

2.  Mammals

3. True

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James has three cubes with identical dimensions. He places the blocks in water, as shown below.
Fantom [35]

Answer:I think it could be A or B but I would choose A.

Explanation:

3 0
3 years ago
The ph of a 0.55 m aqueous solution of hypobromous acid, hbro, at 25.0°c is 4.48. what is the value of ka for hbro?
elena-14-01-66 [18.8K]

The solution would be like this for this specific problem:

Given:

 

pH of a 0.55 M hypobromous acid (HBrO) at 25.0 °C =  4.48

 

[H+] = 10^-4.48 = 3.31 x 10^-5 M = [BrO-] <span>

Ka = (3.31 x 10^-5)^2 / 0.55 = 2 x 10^-9</span>

 

To add, Hypobromous Acid does not require acid adjustment, which is necessary for chlorine-based product and is stable and effective in pH ranges of 5-9.<span>

</span>Hypobromous Acid combines with organic compounds to form a bromamine. Chlorine also combines with the same organic compounds to form a chloramine. <span>It is also one of the least expensive intervention antimicrobial compounds available.</span>

8 0
3 years ago
Read 2 more answers
A 60 ml solution contains 200 ppm of iron. How many milliliters of water must be added to dilute this solution to a final concen
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A girl cycles for 3.00 hrs at a speed of 40.0 km/h. What distance did she ... A train travels at a speed of 30.0 km/hr and travel a distance of 240 km.. How long did it take the ... If a car travels 400 m in 20 seconds how fast is it going? Givens ... is in m/s2. 1. A man hits a golf ball (0.2 kg) which accelerates at a rate of 20 m/s2.

8 0
3 years ago
Imagine you had HCl with a concentration of exactly 0.10 mol/dm3. If 0.023 dm3 of a sodium hydroxide solution, NaOH (aq), could
polet [3.4K]

Answer:

Explanation:

Step 1: Calculate the amount of sodium hydroxide in moles

Volume of sodium hydroxide solution = 25.0 ÷ 1,000 = 0.0250 dm3

Rearrange:

Concentration in mol/dm3 =

Amount of solutein mol = concentration in mol/dm3 × volume in dm3

Amount of sodium hydroxide = 0.100 × 0.0250

= 0.00250 mol

Step 2: Find the amount of hydrochloric acid in moles

The balanced equation is: NaOH(aq) + HCl(aq) → NaCl(aq) + H2O(l)

So the mole ratio NaOH:HCl is 1:1

Therefore 0.00250 mol of NaOH reacts with 0.00250 mol of HCl

Step 3: Calculate the concentration of hydrochloric acid in mol/dm3

Volume of hydrochloric acid = 20.00 ÷ 1000 = 0.0200 dm3

Concentration in mol/dm3 =

Concentration in mol/dm3 =

= 0.125 mol/dm3

Step 4: Calculate the concentration of hydrochloric acid in g/dm3

Relative formula mass of HCl = 1 + 35.5 = 36.5

Mass = relative formula mass × amount

Mass of HCl = 36.5 × 0.125

= 4.56 g

So concentration = 4.56 g/dm3

8 0
2 years ago
Can depletion to the ozone cause changes to the biochemical cycles
GuDViN [60]
Hoi!! 

its true
 
hope this help!!
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3 years ago
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