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irina [24]
3 years ago
8

SCIENCE QUESTION plz helpz

Chemistry
1 answer:
kvasek [131]3 years ago
5 0

Molecule: two or more different or same atoms chemically bonded together. A mixture contains two or more substances, that are not chemically bonded together. A compound is a pure substance, while a mixture is not.

You might be interested in
* Who can help with this lol *
Viktor [21]

Answer: subduction and sea floor spreading

Explanation:

He knew that the continents today were once joined together by fossil records of plants and animals that were found to be on continents far removed from each other. He knew this also by corresponding land forms that matches up as well. What he couldn’t prove is how the land masses would have moved so far away from each other. Subduction and sea floor spreading move the tectonic plates that the continents sit on. That’s what he was missing.

5 0
3 years ago
A car with a mass of 1.1 × 103 kilograms hits a stationary truck with a mass of 2.3 × 103 kilograms from the rear end. The initi
d1i1m1o1n [39]
The answer is C : 15.7 m/s
Use the idea of : momentum before collision = momentum after collision

Before collision;
For car:mass=1.1×10^3, velocity=22
For truck:mass=2.3×10^3, velocity=0
After collision;
For car:mass=2.3×10^3, velocity=-11
For truck:mass=2.3×10^3, velocity=V
(1.1×10^3 × 22) + (2.3×10^3 × 0) = (1.1×10^3 × -11) + (2.3×10^3 × V)
24200 = -12100 + 2.3×10^3V
2.3×10^3V = 36300
V = 15.7 m/s
6 0
2 years ago
Read 2 more answers
Calculate the how many sodium atoms must react completely to give 33,6 dm³ hydro-
lions [1.4K]

To give 33.6 dm³ hydrogen gas at STP, 18.06 x 10²³ atoms of Na must react completely.

<h3>What is Mole concept ?</h3>

A mole is a unit of measurement used to measure the amount of any fundamental entity (atoms, molecules, ions) present in the substance.

As according to the given equation, 2 moles (ie 12.04 x 10²³ atoms) of Na-atoms produces 1 mole (22.4 ltr) of H₂-gas.

Hence, to produce 33.6 ltr (equivalent to 33.6 dm³) of H₂-gas produced by ;

   = 12.04 x 10²³ atoms of Na / 22.4 ltr of H₂-gas x 33.6 ltr

   = 18.06 x 10²³ atoms of Na

Hence, To give 33.6 dm³ hydrogen gas at STP, 18.06 x 10²³ atoms of Na must react completely.

Learn more about Mole concept here ;

brainly.com/question/20483253

#SPJ1

8 0
2 years ago
Two litres of an ideal gas at a pressure of 10 atm expands isothermally into a vacuum until its total volume is 10 litres. How m
nlexa [21]

Answer:

The work done and heat absorbed are both -8,1 kJ

Explanation:

The work done in an isobaric process is defined as:

W = -P (Vf - Vi)

Where P is pressure ( 10 atm)

Vf = 10 L

Vi = 2 L

Thus, <em>W = -80 atm×L ≡ -8,1 kJ</em>

This is the work done in expansion of the gas.  As the gas remains at the same temperature, there is no change in internal energy doing that all work was absorbed as heat.

I hope it helps!

4 0
3 years ago
Write a paragraph about Space Manned Exploration (100 pts)
sashaice [31]
Space Manned Exploration, more commonly known as Human spaceflight, is a type of space travel that launches to space with a spacecraft, including crews or regular passengers. The very first launching program that NASA made was back in 1958 was the Project Mercury with the goal for the first human put into Earth's orbit to survive and come back safely. Other famous spaceflights include the 1969's first moon landing of <span>Neil Armstrong and Edwin "Buzz" Aldrin. Today, NASA has confirmed another attempt to make a spaceflight to the moon in 2020 or 2023. We aren't far from those dates, so let's see what they can do! 


</span>
8 0
2 years ago
Read 2 more answers
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