1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
zvonat [6]
3 years ago
13

List three differences between the earth 240 million years ago and the present earth.

Chemistry
1 answer:
raketka [301]3 years ago
4 0
Dinosaurs, cavemen, sabertooth tiger
You might be interested in
A sample of nitrogen gas, stored in a 2.96-L container at 32.0°C, exerts a pressure of 4.27 atm. Calculate the number of moles o
inysia [295]

<u>Answer:</u> The number of moles of nitrogen gas is 0.505 moles.

<u>Explanation:</u>

To calculate the number of moles of nitrogen gas, we use ideal gas equation, which is:

PV=nRT

where,

P = pressure of the gas = 4.27 atm

V = Volume of the gas = 2.96 L

T = Temperature of the gas = 32.0^oC=[32.0+273]K=305K

R = Gas constant = 0.0821\text{ L. atm }mol^{-1}K^{-1}

n = number of moles of gas = ?

Putting values in above equation, we get:

4.27atm\times 2.96L=n\times 0.0821\text{ L atm }mol^{-1}K^{-1}\times 305K\\n=0.505mol

Hence, the number of moles of nitrogen gas is 0.505 moles.

6 0
4 years ago
Read 2 more answers
86.94 meters to centimeters 8,694
ivanzaharov [21]

True it is 8,694 cm

Hope it helps!

5 0
3 years ago
What is the object called that burns as it enters the atmosphere and causes an shooting star?
nataly862011 [7]

Answer:

A meteor is an asteroid or other object that burns and vaporizes upon entry into the Earth's atmosphere; meteors are commonly known as "shooting stars." If a meteor survives the plunge through the atmosphere and lands on the surface, it's known as a meteorite.

Explanation:

7 0
3 years ago
If you have an atom with 8 protons, 9 neutrons and 10 electrons, what is its mass number?
djverab [1.8K]
17 is the atomic mass
6 0
4 years ago
To practice Problem-Solving Strategy 11.1 Energy efficiency problems. Suppose that you have left a 200-mL cup of coffee sitting
Illusion [34]

Answer:

efficiency of heating with this oven is 51 %

Explanation:

to raise the temp of 200 ml of coffee from 30°C to 60°C the energy input to microwave oven is:

1100 J/s x 45 = 49,500 J  

AT 100% efficiency

For 1°C the energy required to raise the temperature of 1 ml = 4.2 J

So for 30 C°, 1°C the energy required to raise the temperature of 200 ml =

Q = (4.2) (200)(30) = 25,200 J

efficiency = 25,200/49,500 = 0.51 = 51%  

6 0
3 years ago
Read 2 more answers
Other questions:
  • Calculate the hydroxide ion concentration [oh-] for human urine (ph = 6.2). notice this is about hydroxide.
    5·1 answer
  • Q7. Aluminum is extracted from the ore bauxite, which is impure aluminum oxide. 1 tonne (1000 kg) of the ore was found to have t
    14·2 answers
  • Sodium metal reacts with chlorine gas in a combination reaction. Write a balanced equation to describe this reaction. Click in t
    5·1 answer
  • What is the heat of reaction (AH) of the<br> following?<br> C(s) + O2 (g) --&gt; CO2 (g)
    10·1 answer
  • What is the standard reduction potential, E, for the half-reaction Al(aq) +
    12·1 answer
  • For each element write the Noble gas notation
    7·1 answer
  • A food that supplies HIGH AMOUNTS OF VITAMINS AND MINERALS is known as a(n) *
    7·2 answers
  • What scientist said we cannot predict an exact position of<br> atoms.
    12·1 answer
  • What will a soccer player need to do to change a ball’s position?
    9·2 answers
  • assuming the magnesium ribbon wasn't sufficiently polished to remove a coating of magnesium oxie on the surface. how would this
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!