Whats do you want to know?
Answer:
One of the errors for low percentage of magnesium could be because not all the magnesium may have reacted.
Explanation:
During the heating process, if the magnesium have not reacted completely, it can lead to low percentage of magnesium in the oxide formed. The product may still look a bit greyish rather than whitish after the heating process.
Sodium is the reducing agent because a reducing agent is always the donor of electrons.
The average speed :
1. 10.44 m/s
2. 10.42 m/s
3. 9.26 m/s
The distance 100 m have the greatest average speed
<h3>Further explanation
</h3>
Given
Distance and time of runner
Required
Average speed
Solution
<em>
Average speed : total distance : total time
</em>
1. d = 100 m, t = 9.58 s
Average speed : 100 : 9.58 = 10.44 m/s
2. d=200 m, t=19.19 s
Average speed : 200 : 19.19 = 10.42 m/s
3. d=400 m, t = 43.18 s
Average speed : 400 : 43.18 = 9.26 m/s
The distance 100 m have the greatest average speed
1.Type of bonding in which electrons are completely transferred is called ionic bond.
2. Isotopes have same atomic number but different atomic mass number.
Atomic number = number of protons + number of neutrons
Therefore, A is correct.
3. Nucleus is composed of neutrons and protons.
4. Chemical reactions follows the law of conservation of mass. Therefore mass of reactant = mass of product = 4 grams.
5. Again, mass of table salt formed should be equal to mass of (Na+Cl₂) = 4 grams.