1. Different ideas from different scientists (such as schleiden and schwann)
2. B. Describe and examine cells
3. Sorry i don't remember this
hope this helps :)
Heat energy xxxxxxxxxxxxxx
From the periodic table, beryllium has an atomic number 4. This means that beryllium has 4 electrons.
Now, the first energy level can hold only 2 electrons (which will occupy the s sublevel) wile the remaining two electrons will occupy the second energy level (also in the s sublevel).
Based on the above, the electronic configuration of beryllium will be as follows:
1s2 2s2
The reaction between hydrogen and oxygen to form water is given as:

The balanced reaction is:

According to the balanced reaction,
4 g of hydrogen (
) reacts with 32 g of oxygen (
).
So, oxygen reacted with 29.4 g of hydrogen is:

Hence, the mass of oxygen that is reacted with 29.4 g of hydrogen is 235.2 g.