Answer:
c. hydrogen bonding.
Explanation:
Hydrogen bonding occurs when hydrogen is covalently bonded to a highly electronegative atom such as oxygen, flourine, nitrogen etc.
Hydrogen bonds are quite strong and are known to lead to elevated boiling points. As a result of hydrogen bonding, ammonia is known to have a high melting and boiling point compared to its relative molecular mass.
Answer:
I believe the answer is A.
Explanation:
This section states that protozoa live in all bodies of water therefore B can not be an answer because it says protozoa dose not live in any body of water.
I hope this answers your question.
Answer:
Non-zero digits are always significant.
Any zeros between two significant digits are significant.
A final zero or trailing zeros in the decimal portion ONLY are significant. If a number ends in zeros to the right of the decimal point, those zeros are significant.
Explanation:
1.138 has 4 significant figures, which are 1, 1, 3 and 8. The numbers after the decimal point are decimals and are significant figures.
Answer:
Total pressure = 16.42× 10⁻⁹atm
Explanation:
Given data:
Moles of H₂ = 2.50 × 10⁻³ mol
Moles of He = 1.00 × 10⁻³ mol
Mass of Ne = 3 × 10⁻⁴ mol
Volume = 10 L
Temperature = 35°C
Total pressure = ?
Solution:
Pressure of hydrogen:
P = nRT / V
P = 2.50 × 10⁻³ mol× 0.0821 atm. L.mol⁻¹ .k⁻¹ × 308 K / 10 L
p = 63.22× 10⁻³ atm. L /10 L
P = 6.3 × 10⁻³atm
Pressure of helium:
P = nRT / V
P = 1.00 × 10⁻³ mol× 0.0821 atm. L.mol⁻¹ .k⁻¹ × 308 K / 10 L
p = 25.29 × 10⁻³ atm. L /10 L
P = 2.53× 10⁻³ atm
Pressure of neon:
P = nRT / V
P = 3 × 10⁻⁴ mol× 0.0821 atm. L.mol⁻¹ .k⁻¹ × 308 K / 10 L
p = 75.86× 10⁻³ atm. L /10 L
P = 7.59× 10⁻³ atm
Total pressure of mixture:
P(mixture) = pressure of hydrogen + pressure of helium+ pressure of neon
P(mixture) = 6.3 × 10⁻³atm + 2.53× 10⁻³ atm + 7.59× 10⁻³ atm
P(mixture) = 16.42× 10⁻⁹atm
The answer is SiO2
Since silicon has four valence electrons and each oxygen has 2, for every 1 silicon there must be 2 oxygen to fill in both element's outer shells satisfactorily. An alternative way to figure out the chemical formula is to simply swap the charges.
Silicon is a -4 and oxygen is a -2.
Oxygen's charge is brought down into subscript and set as the number of silicons in the chemical formula, making silicon Si2. Silicon's charge is brought down to make the number of oxygens in the chemical formula O4. The formula we have currently is Si2O4. Simplify it to get the empirical formula (divide by 2) and you get SiO2.
