Answer is: synthesis.
Chemical reaction: Ba + F₂ → BaF₂.
Synthesis is type of reaction where two or more compounds (in this reaction barium and fluorine) react to form one product (in this reaction BaF₂).
BaF₂ - barium fluoride, salt, <span>white cubic crystals, soluble in methanol and ethanol.</span>
Answer:
THEY ALL INVOLVE FIGHTING PATHOGENS
Explanation:
The immune system which is involved in defending the body against infections are diseases involves three lines of defense which are all involved in fighting against pathogens. Pathogens are invaders which when introduced into the body causes harm and therefore makes us sick. The body's first line of defense includes the physical barriers such as the skin, mucous membrane; chemical barriers such as tears, saliva, gastric acid in the stomach. These helps to keep the pathogens from entering the delicate parts of the body and once the pathogens find their way out of the reach of the first line of defense, the second line of defense is initiated. This includes inflammatory effects, swelling, redness, phagocytosis by neutrophils and macrophages. The third line of defense is the actions of lymphocytes which acts on invading microbes. The lymphocytes are of two types; the B and T cells. B cells produces antibodies which fight the antigens and T cells attack the infected cells of the body. There is also the memory cells which keeps information about the invading microbes for future attacks. This enables the body to respond swiftly when next the same type of pathogens attack.
Answer is: there is 2,69·10²³ atoms of bromine.
m(CH₂Br₂) = 39,0 g.
n(CH₂Br₂) = m(CH₂Br₂) ÷ M(CH₂Br₂).
n(CH₂Br₂) = 39 g ÷ 173,83 g/mol.
n(CH₂Br₂) = 0,224 mol.
In one molecule of CH₂Br₂, there is two bromine atoms, so:
n(CH₂Br₂) : n(Br) = 1 : 2.
n(Br) = 0,448 mol.
N(Br) = n(Br) · Na.
N(Br) = 0,448 mol · 6,022·10²³ 1/mol.
n(Br) = 2,69·10²³.
Answer:Phase changes require either the addition of heat energy (melting, evaporation, and sublimation) or subtraction of heat energy (condensation and freezing). ... Changing the amount of heat energy usually causes a temperature change.
Explanation:
To calculate the number of atoms of Cr, we first find the number of moles per unit of cubic centimeter of Cr. Then, use avogadros number for the number of atoms. Calculations are as follows:
1 cm^3 (7.15 g/cm^3) (1 mol / 51.996 g Cr) = 0.14 mol Cr
0.14 mol Cr ( 6.022 x 10^23 atoms Cr / 1 mol Cr ) = 8.28 x 10^22 atoms Cr
