1) This is a definition.
2) Protons are given by the bottom number (since atomic number = number of protons).
3) Neutrons = (mass number)-(atomic number), which are the top and bottom numbers, respectively.
4) Nuclear fusion involves combining two things together, which is only reflected by the last option.
5) This is a fact.
6) This is a fact.
7) This is a fact.
8) This is a fact.
9) The correct option is the explanation.
Answer:
d. white blood cells
Explanation:
It is the white blood cells that have the least tendency to cross the blood- brain barrier.
Blood- brain barrier is psychological barrier and restricts substances that circulate into the blood from crossing over the central nervous system.
Water, glucose as well as sodium ions can easily cross the barrier. As these are good for body supply energy to the brain.
Answer:
When energy is removed in liquid water then it will solidify since heat is given off by the system to its surrounding. It is an exothermic process where the enthalpy decreases since heat is taken off. So liquid water becomes ice in an exothermic process.
Explanation:
Answer:
Option D. KBr < KCl < NaCl
Explanation:
We'll begin by calculating the number of mole of each sample.
This can be obtained as follow:
For NaCl:
Mass = 1 g
Molar mass of NaCl = 23 + 35.5 = 58.5 g/mol
Mole of NaCl =?
Mole = mass /Molar mass
Mole of NaCl = 1/58.5
Mole of NaCl = 0.0171 mole
For Kbr:
Mass = 1 g
Molar mass of KBr = 39 + 80 = 119 g/mol
Mole of KBr =?
Mole = mass /Molar mass
Mole of KBr = 1/119
Mole of KBr = 0.0084 mole
For KCl:
Mass = 1 g
Molar mass of KCl = 39 + 35.5 = 74.5 g/mol
Mole of KCl =?
Mole = mass /Molar mass
Mole of KCl = 1/74.5
Mole of KCl = 0.0134 mole
Summary
Sample >>>>>>>> Number of mole
NaCl >>>>>>>>>> 0.0171
KBr >>>>>>>>>>> 0.0084
KCl >>>>>>>>>>> 0.0134
Arranging the number of mole of the sampl in increasing order, we have:
KBr < KCl < NaCl
