Answer: The mass of electrons is mostly ignored because electrons are extremely small compared to neutrons and protons.
Explanation: A proton is about 1,836 times the size of an electron.
On the periodic table, the atomic number for each element can be found. This number is found by measuring the weight of 6.02 x 10^23 atoms of the element in grams. Electrons aren't ignored when finding exact math, but for the sake of simplification high school teachers will generally have you only count the number of protons and neutrons when calculating the mass of atoms.
D there is one kind of cell of which all living things are made
The answer would be "air, wood". Gases have the highest Kinetic energy and least Potential energy. Liquids have the 2nd highest Kinetic energy and 2nd least potential energy and solids have the least kinetic energy and highest potential energy.
Answer:
Endothermic
It absorbs heat
1.20 × 10³ kJ
Explanation:
Let's consider the following thermochemical equation.
2 H₂O(l) → 2 H₂(g) + O₂(g) ΔH = 572 kJ
Since ΔH > 0, the reaction is endothermic, that is, it absorbs heat when H₂O reacts.
572 kJ are absorbed when 36.03 g of water react. The heat absorbed when 75.8 g of H₂O react is:
75.8 g H₂O × (572 kJ/36.03 g H₂O) = 1.20 × 10³ kJ