Answer:
i believe the answer is B.
Explanation :
Gravity is the force by which a planet or other body draws objects toward its center. The force of gravity keeps all of the planets in orbit around the sun.
The average atomic mass of the element is the weighted average atomic mass of element with respect to the natural abundance of all the isotopes.
isotopes are atoms of the same elements with different mass numbers , in other words same number of protons but different numbers of neutrons.
to find the average atomic mass we need to know the atomic masses of all the isotopes in addition to the natural abundance percentages of the isotopes.
answer is we need to know the atomic masses of the isotopes as well
Answer:
1.16L
Explanation:
First, let us generate the balanced equation for the reaction. This is illustrated below
2Mg + O2 —> 2MgO
Now let us covert 2.5g of Mg given in the question to moles. This is illustrated below:
Molar Mass of Mg = 12g/mol
Mass of Mg = 2.5g
Number of mole of Mg =?
Number of mole = Mass /Molar Mass
Number of mole of Mg = 2.5/24 = 0.104mole
From the equation,
2moles of Mg required 1mole of O2.
Therefore, 0.104mole of Mg will require = 0.104/2 = 0.052mole of O2
Now let us calculate the volume occupy by 0.052mole of O2. This is shown below.
1mole of a gas occupy 22.4L at stp
Therefore, 0.052mole of O2 will occupy = 0.052 x 22.4 = 1.16L
Therefore, 1.16L of O2 is required for the reaction
Answer:
Flood barriers
Explanation:
Many towns in flood-prone areas are surrounded by flood barriers that are built to hold back rising water during seasonal highs.
- Flood barriers are water resistant walls that are used to prevent breaking water during a high period of inundation from their channels.
- They are usually vertical artificial structures which can be temporary or permanent.
- They help to hold or contain the flood water during the high season.
- These walls prevents flood plains and other nearby areas from getting flooded during the rainy season.
