Hey there! Hello!
In order for water to be formed, or for any reaction to occur, there needs to be something that splits the current bonds of hydrogen and oxygen up. In this case, some sort of activation energy is required.
Hydrogen and oxygen are not found as single molecules in nature. They're found as 2 molecules linked together, as H2 and O2. An activation energy, such as heat, or some sort of catalyst needs to be used in order to split the two molecules up and make them link with one another.
What happens afterwards is a chemical reaction that involves the valence electrons of oxygen (which has 6 on the outermost shell) and hydrogen (which has two on the outermost shell). The oxygen wants to have an octet (8 valence electrons) total, so it shares with the hydrogen, which is already satisfied with it's two valence electrons (according to the nature of hydrogen).
But because there has to be a total of four molecules involved, two molecules of water are going to be produced as a result.

Hope this helped you out! Feel free to ask me any additional questions if you need further clarification. :-)
This process is known as fertilisation. Gametes contain half the number of chromosomes of all other cells in the organism. This means they are haploid . When the male and female gametes combine in fertilisation they create an embryo with the full complement of chromosomes (diploid).
Answer:b
Explanation:
From the question, the stoichiometry of the balanced reaction equation showed that 180gof glucose give 134.4L of CO2. Then we are given to find the volume of carbon IV oxide given off by 126g of glucose. This is done as shown in the image by relating what is given to the stoichiometry of the balanced reaction equation to obtain the answer as shown.
<h2>A sample of gold (Au) has a mass of 72.04g. Calculate the number of atoms of gold (Au): It is equal to ==2.207 x 10²³ number of atoms </h2>
Explanation:
we can find number of atoms in a given sample by the formula :
Number of atoms = Given mass /atomic mass x Avogadro's number
or , it can be written as :
Number of atoms = given mass /atomic mass x 6.022 x 10²³
Now in above asked question , the values given are :
Mass of sample of gold = 72.04g
Atomic mass of gold : 196.6
Avogadro's number = 6.023 x 10²³
so, using the above formula we have :
Number of atoms = 72.04 /196.6 x 6.022 x 10²³
= 0.3664 x 6.022 x 10²³
=2.207 x 10²³ number of atoms