Answer:
Explanation:
Calcium is all around us. The average human contains approximately 1kg of calcium, of which 99% is stored in our bones. It is the 5th most abundant element in the earth's crust, occurring widely as calcium carbonate which is more commonly known as limestone. It is also the fifth most abundant dissolved ion in seawater.
Answer:
Some of the physical changes used by the industrial chemist in order to identify it is by scratching it with other metals in order to find the hardness of it. Trying to deform it in order to find the malleability, and to heat it and measure the temperature in order to find the melting point.
Some of the chemical changes used by the industrial chemist in order to identify it is by inserting it in water to observe that whether it reacts with it or not, if the reaction is violent, then the metal belongs to either group I or group II. The other method is to insert it in acids of distinct strength and to observe its reaction. The metals belonging to the second group react briskly with acids. The other metals react gradually with acids and others are almost inert.
Answer:
2.05moles
Explanation:
The balanced chemical equation in this question is as follows;
Sn + 2H2SO4 → SnSO4 + SO2 + 2H2O
Based on the above equation, 2 moles of H2SO4 reacted to produce 1 mole of SnSO4
However, the mass of SnSO4 produced is 219.65 grams. Using mole = mass/molar mass, we can find the number of moles of SnSO4 produced.
Molar mass of SnSO4 where Sn = 118.7, S = 32, O = 16
= 118.7 + 32 + 16(4)
= 150.7 + 64
= 214.7g/mol
mole = 219.65/214.7
mole = 1.023mol
Therefore, if 2 moles of H2SO4 reacted to produce 1 mole of SnSO4
1.023 mol of SnSO4 produced will cause: 1.023 × 2/1
= 2.046moles of H2SO4 to react.
Answer:
Bi (Bismuth)
Ag (Silver)
Li (Lithium)
Explanation:
Xe (Xenon) and I (Iodine) are non-metals. They cannot from a metallic bond because metallic bonds are bonds between metals only.
Answer: There are few simple rules to follow.
(1) The atomic number is equal to the number of protons.
Z
= number of protons
(2) In neutrally charged elements, the number of electrons is the same as the number of protons.
Z
= number of protons = number of electrons (no charge)
Otherwise, positive charge means that the element lost an electron and negative charge means it gained an electron.
(3) The atomic mass is equal to the sum of the number of protons and number of neutrons.
A
= number of protons + number neutrons
or
A
=
Z
+ number neutrons
So if you say that
Z
= 20 and
A
= 40, then
A
=
Z
+ number neutrons
40 = 20 + number of neutrons
40 - 20 = number of neutrons
Therefore,
number of neutrons = 20
Explanation:
