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8_murik_8 [283]
3 years ago
6

Evidence for past events in Earth's ancient history are provided by:

Chemistry
1 answer:
g100num [7]3 years ago
7 0
Rocks and the fossils within them!
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How many gallons of water in lake lewisville?
Vlada [557]
1.422 × 10^11 us liquid gallons
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3 years ago
How many grams of O2 are needed to react with 18.2 g of NH3?
erastova [34]

Answer:

44 g oxygen are needed.

Explanation:

Given data:

Mass of oxygen needed = ?

Mass of ammonia = 18.2 g

Solution:

Chemical equation:

4NH₃ + 5O₂   →  4NO + 6H₂O

Now we will calculate the number of moles of ammonia:

Number of moles = mass/molar mass

Number of moles = 18.2 g/ 17 g/mol

Number of moles = 1.1 mol

Now we will compare the moles of ammonia with oxygen from balance chemical equation.

                        NH₃              :                O₂

                          4                 :                 5

                          1.1                :              5/4×1.1 = 1.375 mol

Mass of oxygen needed:

Mass = number of moles × molar mass

Mass = 1.375 mol × 32 g/mol

Mass = 44 g

4 0
3 years ago
A car with a mass of 1,000 kg is moving at a speed of 20 m/s. What is the car's kinetic energy?
shtirl [24]

The answer would be 200000 J. the equation for kinetic energy is 1/2 mass times velocity squared. 1/2 of 1,000 is 500. and 20*20 is 400. So, multiply 400 by 500, and that gives you your answer,

7 0
2 years ago
How many significant figures are in 5.76 e 15​
Dvinal [7]

Answer: 3 significant figures

Explanation: because in scientific notation only the before and after decimal number are considered but in standard form all numbers including exponents are all significant figures

5 0
3 years ago
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A large piece of iron was reacted with an acid. What would happen to the rate of the reaction had the large piece been finely di
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The reaction occurs in a similar way as magnesium does, but much less vigorous. Strong heating is required to make iron powder burn in oxygen. The reaction gives out a yellow showery sparks and produces a black solid. iron reacts with dilute hydrocloric acid to give iron chloride and hydrogen gas.
3 0
3 years ago
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