Answer:
B. Carry oxygen, nutrients, waste, & to fight pathogens
Explanation:
The circulatory system refers to all organs and tissues involved in carrying blood and lymph around the body.
The circulatory system carries oxygenated blood from the heart to cells and deoxygenated blood back to the heart.
Nutrients are carried in the blood to cells in different parts of the body and waste products are also carried from cells in the blood.
White blood cells is a component of blood in the circulatory system that fights off diseases.
Answer:
d. delta H is positive, and delta S is positive
Explanation:
The process of dissolution of NH4Cl is:
NH4Cl(s) → NH4+(aq) + Cl-(aq)
As the solution is cooled, the process is absorbing energy, that means ΔH > 0. (ΔH < 0 when the heat is released).
As there are produced 2 ions from 1 solid molecule, the disorder is increasing and ΔS > 0
The right answer is:
<h3>d. delta H is positive, and delta S is positive</h3>
Answer: Rutherford's model was the first propose of the existence of small, dense nucleus's.
Explanation: The atom, as described by Ernest Rutherford, has a tiny, massive core called the nucleus. The nucleus has a positive charge. Electrons are particles with a negative charge. Electrons orbit the nucleus. The empty space between the nucleus and the electrons takes up most of the volume of the atom.
Answer:
(a) The amount of O2 needed is 2.67 pounds.
(b) The volume required is 847,509 litres.
(c) The heat given off as a result of the combustion to CO2 is 393.5 kJ.
Explanation:
For a complete combustion of C to C02(g)
(a) The molecular mass of O2 is 32 g/mol and the molecular mass of C is 12 g/mol.
We need 1 mol O2 to burn 1 mol of C.
If we need 32 g of O2 to burn 12 g of C, to burn 1 pound of pure carbon charcoal we need (32/12)*1=2.67 pounds of O2.
(b) The density of O2, at atmospheric conditions, is 1.429 g/l. The volume of 2.67 pounds of O2 is
(c) To calculate the heat of the reaction, we have to look up in the Table of Standard Enthalpy of Formation Values and compute the following equation
The heat given off as a result of the combustion to CO2 is 393.5 kJ.
Answer:
The model was the result of hundreds of years of experiments. however we have had modifications.
Explanation: