Answer:
mNaCl = mNa + mCl
mNa = 20g
mCl = mCl2/2 = 30/2 = 15g
mNaCl= 20+15 = 35g
Whereas ionic bonds join metals to non-metals, metallic bonding joins a bulk of metal atoms. ... Sodium metal is therefore written as Na, not Na+. ... Both of these factors increase the strength of the bond still further. ... Heat capacity: This is explained by the ability of free electrons to move about the solid.
2200 mg of antibiotic
Explanation:
Given that 40 mg of antibiotic/kg of the bodyweight is given.
If patient is 55 kg then the dose of antibiotic will be
if 40/1000000 is done then we can get antibiotic in kg/kg of the weight
= 0.00004 kg of antibiotic per kg
0.00004*55 ( to know how much 55 kg person will require)
= 0.0022 kg
This 0.0022 value will be converted to mg
0.0022*10^6
= 2200 mg of antibiotic will be given to a 55kg patient.
Answer: A) grinding coffee beans
Explanation:
A physical change is defined as a change in which there is alteration in shape, size etc. No new substance gets formed in these reactions.
A chemical change is defined as a change in which a change in chemical composition takes place. A new substance is formed in these reactions.
1. Grinding coffee : Only change in size takes place, thus a physical change
2. Baking a cake: the chemical reaction occurs by combination of flour with oxygen , thus a chemical change.
3.:converting water to hydrogen and oxygen: The decomposition iof water takes place, thus is a chemical change
4.Burning of coal: the chemical reaction occurs by combination of carbon with oxygen , thus a chemical change.
6.9 x 10^-4 would be .00069 written in scientific notation