As per the given chemical formula- Na2CO3.10H2O, one mole of the chemical compound contains 13 moles of oxygen atoms. Hence
Number of moles of oxygen atoms in one mole of Na2CO3.10H2O = 13
number of moles of oxygen atoms in 0.2 moles of Na2CO3.10H2O = 13 X 0.2 = 2.6
Now, one mole of a substance contains 6.022 X 10^23 particles of the substance. Thus
number of atoms of oxygen in one mole of oxygen atom = 6.022 X 10^23
number of moles of oxygen atoms in 2.6 moles of oxygen atoms = 2.6 X 6.022 X 10^23 = 15.657 X 10^23
= 1.566 X 10^24
Thus, there are 1.566 X 10^24 atoms of oxygen in 0.2 moles of Na2CO3.10H2O.
4.7
Answer:
Amount of heat absorbed by water is 2604.54 J.
Explanation:
Amount of heat absorbed by water = 
where m represents mass, C represents specific heat and 
represents change in temperature.
Here 
g , 
and = (final temperature - initial temperature) = (29.5-21.2) 
= 8.3
So, amount of heat heat absorbed by water
= 
= 2604.54 J
Drugs interfere with the way neurons send, receive, and process signals via neurotransmitters. Some drugs, such as marijuana and heroin, can activate neurons because their chemical structure mimics that of a natural neurotransmitter in the body. This allows the drugs to attach onto and activate the neurons. Although these drugs mimic the brain’s own chemicals, they don’t activate neurons in the same way as a natural neurotransmitter, and they lead to abnormal messages being sent through the network.
Other drugs, such as amphetamine or cocaine, can cause the neurons to release abnormally large amounts of natural neurotransmitters or prevent the normal recycling of these brain chemicals by interfering with transporters. This too amplifies or disrupts the normal communication between neurons.
1. <span>Substances in a </span>mixture<span> can be separated using different </span>methods, for example <span>distillation (separation of two liquids).
2. </span>Mass<span> is the amount of matter an object contains.
</span>Volume is t<span>he amount of space occupied by a three-dimensional object.
3. d(wallet) = 15g</span>÷5cm³ = 3g/cm³.
4. Weight of an astronaut also increases. W=m·g.
