Explanation:
Physical change -
It refers to any change during any process , where there is no new substance is formed , is referred to as a physical change.
Any change in the state of matter is characterised under physical change.
Chemical change -
It refers to any change in a chemical process , where there is formation of any new substance , is referred to as a chemical change .
From the options given in the question,
1. Apple turning brown , on air exposure , is an example of chemical change .
2. The physical state of mercury is liquid , is an example of physical change .
3. phosphorus burns on exposed to air , is an example of chemical change .
4. The gas Neon is colorless at the room temperature , is is an example of physical change .
1. 2Al(s)+6HCl(aq)⇒2AlCl₃(aq)+3H₂(g)
2. 2AgNO₃ (aq) + Cu (s)⇒Cu(NO₃)₂ (aq) + 2Ag (s)
3. 2C₃H₈O(l) + 9O₂(g) ⇒ 6CO₂(g) + 8H₂O(g)
<h3>Further explanation</h3>
There are several reactions that can occur in a chemical reaction: single replacement, double replacement, synthesis, decomposition or combustion, etc.
1.Al(s)+HCl(aq)⇒AlCl₃(aq)+H₂(g)
type : single replacement
balance :
2Al(s)+6HCl(aq)⇒2AlCl₃(aq)+3H₂(g)
2. AgNO₃ (aq) + Cu (s) ⇒ Cu(NO₃)₂ (aq) + Ag (s)
type : single replacement
balance :
2AgNO₃ (aq) + Cu (s)⇒Cu(NO₃)₂ (aq) + 2Ag (s)
3. C₃H₈O + O₂ ⇒ CO₂ + H₂O
type : combustion of alcohol
balance :
2C₃H₈O(l) + 9O₂(g) ⇒ 6CO₂(g) + 8H₂O(g)
Answer:
I believe the organelle should replace the question mark!
The top number on elements in the periodic table is the atomic number, so when you look at the periodic table you can see that 42 is Mo (Molybdenum), and this is the only element with that atomic number.
Hope this helped! Please rate 5 starts and hit thanks if it did :)
The number of atoms N = 5.8 x 10²¹
<h3>Further explanation</h3>
A mole is a unit of many particles (atoms, molecules, ions) where 1 mole is the number of particles contained in a substance that is the same amount as many atoms in 12 gr C-12
1 mole = 6.02.10²³ particles
mass of N in 0.82 g of NaNO₃ (MW NaNO₃: 85 g/mol) :

moles of N :

The number of atoms N :
