b. Pyrite
c. Quartz
d. Calcite
(1) Sodium has a melting point of 371 K.
(2) Sodium has a molar mass of 23 grams.
(3) Sodium can conduct electricity in the liquid
phase.
(4) Sodium can combine with chlorine to produce
a salt.
Answer;
(4) Sodium can combine with chlorine to producea salt.
Explanation;
Sodium is an alkali metal (group 1 ) in the periodic table. It is a soft metal, reactive and with a low melting point. It has an atomic weight of 23 grams.
Sodium is a good conductor of electricity due to the presence of delocalized electrons in its metallic structure. It reacts vigorously with water to produce sodium hydroxide and hydrogen.
-When exposed to air, metallic sodium recently cut looses its silvery appearance and acquires an opaque grey color due to the formation of a sodium oxide coating.
Warm water is less dense than cold water.
The density is the same for warm and cold water.
The density will sometimes be higher for warm water and other times higher for cold water.
b. decrease in the number of neutrons in the nucleus of an atom
c. increase in the number of neutrons in the nucleus of an atom
d. change in the number of protons in a nucleus of an atom
Answer: Option (d) is the correct answer.
Explanation:
Transmutation is a process which brings changes in the nucleus occur because of change in the number of protons of an atom. Therefore, the atom formed will have different properties from its parent atom.
For example,
A transmutation can be natural or artificial in nature.
Thus, we can conclude that a transmutation reaction must always involve a change in the number of protons in a nucleus of an atom.
Answer:
gravity
Explanation:
your mass is the same on the moon as is on earth or underwater but your weight changes because of gravity
Given that the molar mass of CO2 is 44.01 g/mol, how many liters of oxygen is required at STP to produce 88.0 g of CO2 from this reaction?
44.8 L
45.00 L
89.55 L
89.6 L
89.6 L of O₂
The balanced chemical equation is as,
CH₄ + 2 O₂ → CO₂ + 2 H₂O
As at STP, one mole of any gas (Ideal gas) occupies exactly 22.4 L of Volume. Therefore, According to equation,
44 g ( 1 mol) CO₂ is produced by = 44.8 L (2 mol) of O₂
So,
88 g CO₂ will be produced by = X L of O₂
Solving for X,
X = (88 g × 44.8 L) ÷ 44 g
X = 89.6 L of O₂