the universe formed through the big bang explosion, all of the elements on Earth have been cooked for billions of years in stars and then released in the universe through super- nova explosions.
Answer:
A
Explanation:
B - Can't be - Ionic bonds are formed by oppositely charged ions
C - Can't be - This is a covalent bond
D - Can't be - This is an induced dipole or a van Der waals attraction
E - This is a permanent dipole dipole attraction
B . microscope
this is the answer .
Answer:
The correct answer is 25 mL graduated cylinder (it should be used in all the cases)
Explanation:
In order to measure 25.00 ml sample of a solution it should be used a 25 mL graduated cylinder, as it is previously and properly calibrated. The other laboratory glassware, beaker and erlenmeyer, have graduations which are approximate, so they are used when exact volumes are not needed.
ii) graduated cylinder has the least uncertainly. It is more accurate than a beaker or erlenmeyer (to within 1%)
iii) A 25 mL graduated cylinder should be used because it is the most accurate lab glassware (between those were mentioned: beaker, erlenmeyer).
Answer: mass m = M·c·V
Explanation: M(CaCl2) = 110.98 g/mol, c= 0.15 mol/l,
n=m/M= cV, volume of Solution is not mentioned
