Answer:
Antibodies are types of proteins in the body that can prevent diseases. Once a vaccine is introduced into the bloodstream, it immediately causes the production of antibodies to occur by using T-cells and B lymphocytes, or at least, most vaccines work like that.
Explanation:
To determine the velocity of an object, you need to know the displacement and the change in time.
v = displacement / change in time
Answer:
32.3 dm³
Explanation:
Data given:
no. of molecules of Cl₂ = 8.7 x 10²³
Volume of chlorine gas (Cl₂) = ?
Solution:
First we have to find number of moles
For this formula used
no. of moles = no. of molecules / Avogadros number
no. of moles = 8.7 x 10²³ / 6.022 x 10²³
no. of moles = 1.44 moles
Now we have to find volume of the gas
for this formula used
no. of moles = volume of gas / molar volume
molar volume = 22.4 dm³/mol
Put values in above equation
1.44 moles = volume of Cl₂ gas / 22.4 dm³/mol
rearrange the above equation
volume of Cl₂ gas = 1.44 moles x 22.4 dm³/mol
volume of Cl₂ gas = 32.3 dm³
Answer:
lever Levers
Types of lever
Levers are all around us. Hammers, axes, tongs, knives, screwdrivers, wrenches, scissors—all these things contain levers.
Explanation:
The heat of the reaction is an extensive property: it is proportional to the quantity of the quantity that reacts.
The change in enthalpy is a measured of the heat evolved of absorbed.
When the heat is released, the change in enthalpy is negative.
The reaction of 2 moles of Na develops 368.4 kj of energy.
Calculate the number of moles of Na in 1.90 g to find the heat released when this quantity reacts.
Atomic mass of Na: 23 g/mol
#mol Na = 1.90 g / 23 g/mol = 0.0826 mol
Do the ratios: [368.4 kj/2mol ] * 0.0826 mol = 15.21 kj.
Then the answer is that 15.21 kj of heat is released (evolved)
