Answer:
Science is the study of the nature and behavior of natural things and the knowledge that we obtain about them. ... A science is a particular branch of science such as physics, chemistry, or biology. Physics is the best example of a science which has developed strong, abstract theories.
Explanation:
Answer:
For this reason, the existence of Mesosaurus helps support the theory of continental drift; that is, the now-well-attested fact that South America and Africa were joined together into the giant continent Gondwana 300 million years ago before the continental plates supporting them broke apart and drifted.
Explanation:
Answer:
6.53g of K₂SO₄
Explanation:
Formula of the compound is K₂SO₄
Given parameters:
Volume of K₂SO₄ = 250mL = 250 x 10⁻³L
= 0.25L
Concentration of K₂SO₄ = 0.15M or 0. 15mol/L
Unknown:
Mass of K₂SO₄ =?
Methods:
We use the mole concept to solve this kind of problem.
>>First, we find the number of moles using the expression below:
Number of moles= concentration x volume
Solving for number of moles:
Number of moles = 0.25 x 01.5
= 0.0375mole
>>Secondly, we use the number of moles to find the mass of K₂SO₄ needed. This can be obtained using the expression below:
Mass(g) = number of moles x molar mass
Solving:
To find the molar mass of K₂SO₄, we must know the atomic mass of each element in the compound. This can be obtained using the periodic table.
For:
K = 39g
S = 32g
O = 16g
Molar mass of K₂SO₄ = (39x2) + 32 + (16x4)
= 78 +32 + 64
= 174g/mol
Using the expression:
Mass(g) = number of moles x molar mass
Mass of K₂SO₄ = 0.0375 x 174 = 6.53g
Answer:
Atomic number is the number of protons in an isotope or element.
Explanation: The atomic number is the same number of protons in an element or isotope and if said isotope is neutral than it is the same number of electrons.
Example: Atomic number = 19 Protons = 19 if neutral Electrons = 19
Answer:
1: [H+] = 0.01 M
2: [H+] = 0.0001 M
3: [H+] = 0.0001 M
Explanation:
Step 1: data given
pH = -log[H+]
pH = pOH = 14
Step 2:
1. A solution with pH = 2.0
pH = 2
-log[H+] = 2.0
[H+] = 10^-2
[H+] = 0.01 M
2. A solution with pH = 4.0
pH = 4
-log[H+] = 4.0
[H+] = 10^-4
[H+] = 0.0001 M
3. A solution with pOH = 10.0
pH = = 14 - 10 = 4
pH = 4
-log[H+] = 4.0
[H+] = 10^-4
[H+] = 0.0001 M
