<span>In H2CO, C is bonded to H, H and O. Write down the valence electrons of each element.
2 H = 1x 2 = 2.
C= 4
O = 6
Total 12 </span>
<h2>
Answer:</h2>
In <u>Combination reaction</u>, two or more elements combined to form one compound of different properties.
- C(s) + O2(g) ⇢ CO2(g).
- H2(g) + O2(g) ⇢ H20(l).
In <u>Displacement reation</u>, the high reactive element displaces the low reactive element and formed compound of different properties.
- Fe(s) + CuSo4(aq) ⇢ FeSo4(aq) + Cu(s).
- AgNO3(aq) + Cu(s) ⇢ CuNO3(aq) + Ag(s).
Answer:
A). An atom is an indivisible hard-sphere.
Explanation:
The 'Atomic Theory' of Dalton is characterized as the earliest model(came in 1803) which described the atoms as the indivisible and resistant spheres. He <u>used the example of watermelon to elaborate that the atoms of a specific element share similar characteristics</u> and the atoms of distinct elements differ in their mass as well as their size. Thus, <u>option A</u> is the correct answer.