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forsale [732]
3 years ago
14

How old was the oldest animal fossil help thx​

Chemistry
1 answer:
JulijaS [17]3 years ago
5 0

Answer:

the Rhyniognatha hirsti

Explanation:

at age 400 million years old

You might be interested in
how many mL of a 3.5 M sodium hydroxide will be needed to neutralize 15mL of a 4.3 M hydrochloric acid solution?
kobusy [5.1K]
Step 1 : write a valanced equation..
NaOH + HCl 》NaCl + H2O

Step 2 : find the number of mole of HCl..
1000 ml ..contains 4.3 mole
15ml... (4.3÷1000)×15 =...

Stem 3 : use mole ratio....
HCl : NaOH
1 : 1
So mole is same as calculated above...

Step 4 :
3.5 mole of NaOH is in 1000ml
(4.3÷1000)×15 mole is in ....


Do the calculation
6 0
3 years ago
If 400 Joules of work is done in 20 seconds, how much power was generated?
Sonbull [250]
To work this out you do 400÷20=20
5 0
3 years ago
What kind of questions CANNOT be answered by chemistry?
Sergeu [11.5K]

Answer:

d. why matter exists

Explanation:

The kind of questions that chemistry CANNOT answer is "why matter exists".

In Chemistry, question of how the properties, composition and structure of substances are is answered. Also, the transformations that these substances undergo, and the energy that they release or absorbe during the transformation processes are revealed in chemistry.

Chemistry can answer the question of what forms of matter exists but cannot answer why matter actually exists.

5 0
3 years ago
N2+3H2-2NH3
NemiM [27]

102 grams of ammonia is formed when 3 moles of nitrogen and 6.7 moles of hydrogen reacts.

Explanation:

The equation given is of Haeber's process in which the nitrogen is limiting factor in the ammonia formation and hydrogen if in excess gets delimited.

We know that 1 mole of Nitrogen gives 2 moles of ammonia.

We have 3 moles of nitrogen here,

So, 6 moles of ammonia will be form

so from the formula

no of moles=mass/atomic mass

           mass= no. of moles*atomic mass

                     = 6*17

                       = 102 grams of ammonia will be formed.

So, 6 moles or 102 grams of ammonia is formed when 3 mole of nitrogen and 6.7 mole of hydrogen reacts.

7 0
3 years ago
What is the force of a 3kg skateboard accelerating at a rate of 4m/s?
Sholpan [36]
To times 4 and 3 together for mass and acceleration then your answer would be 12, So Force= 12
7 0
3 years ago
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