Since cells are hard to see the microscope helped them see. scientist were able to actually see cells in tissues placed under the microscope.
Number of moles = 0.0688 moles of NaoH
volume = 0.250 L
Molarity = moles of solute / volume ( L )
M = 0.0688 / 0.250
M = 0.28 M
Answer B
Answer:
Explanation:
To solve this problem, we must understand the relationship between mass of a substance and the number of atoms.
Atoms are the smallest indivisible particles of any matter. A substance can be made up of several number of atoms in their space.
The mass of any substance is a function of the amount of atoms its contains.
The mass of a substance is related in chemistry to the amount of atoms its contains using the parameter called the number of moles.
A mole is the amount of substance that contains the Avogadro's number of particles. This number is 6.02 x 10²³ particles. The particles here can be protons, neutrons, electrons, atoms e.t.c.
Now,
Number of moles = 
Molar mass of copper = 63.6g/mole
Number of moles =
= 0.03mole
Since 1 mole of a substance contains 6.02 x 10²³atoms
0.03 mole of copper will contain 0.03 x 6.02 x 10²³atoms
= 1.89 x 10²² atoms
He needs to add 1.89 x 10²² atoms to make 2g of the sample.
Depression can affect a person psychologically, it also has the potential to affect physical structures in the brain. These physical changes range from inflammation and oxygen restriction, to actual shrinking. Depression can impact the central control center of nervous system. Depression can cause amygdala to enlarge. This is a part of the brain associated with emotional responses. When amygdala becomes larger and more active, it causes sleep disturbances, changes in activity levels, and changes in other hormones.
Answer:
B
Explanation:
Soil structure affects water and air movement in a soil, nutrient availability for plants, root growth, and microorganism activity. ... This allows for greater air and water movement and better root growth.