Answer:
Atomic #: 82
Mass #: 206
Charge: 4+
# of protons: 82
# of electrons: 78
# of neutrons: 124
Explanation:
Atomic #: look at the bottom left #, it's always the atomic #.
Mass #: look at the top left # it's always the mass #.
Charge: they give you the charge which is shown on the upper right of the element.
# of protons: is the atomic #
# of electrons: also the atomic # minus 4 bc the charge is a positive 4, indicating that some electrons 'left'.
# of neutrons: 206 (mass # is protons + neutrons) minus 82 (atomic#) which is 124.
Answer:
due to the bicarbonate of CaCO3
Answer:
B)
Explanation:
Dalton was the first scientist to propose an atomic model. He said that each element is composed of extremely small particles called atoms, which are indivisible, atoms of a given element are identical, and atoms of different elements have different properties.
With the advance of the studies, it was proven that elements are composed of small particles, atoms and that the atoms of each element are identical, and have different properties from atoms of different elements.
But, now we know that the atom can be divisible: it's formed by electrons, protons, and neutrons. So only postulate <em>ii</em> is no longer considered valid.
The concentration of solution : 0.2 M
<h3>Further explanation</h3>
Given
5.6 g Potassium hydroxide(KOH)
500 ml of solution = 0.5 L
Required
The concentration
Solution
Molarity shows the number of moles of solute in every 1 liter of solution or mmol in each ml of solution
MW KOH = 39+16+1=56 g/mol
mol solute(KOH) :
= mass : MW KOH
= 5.6 : 56 g/mol
= 0.1
Molarity :
= 0.1 : 0.5
= 0.2 M
Pure Substance- Element
Explanation:
Pure Substance VS. Mixture:
A pure Substance CANNOT be separated by physical changes, but a Mixture can.
PURE SUBSTANCE: Element VS. Compound:
An Element is one simple atom while a compound is two or more.
Example: Al (Aluminum) is an Element. CaCl (Calcium Chloride) is a compound.
You can split a compound with chemical changes because if you were to take the example, it would be a Calcium atom and a Chlorine atom.
You CANNOT split a single atom (Element) unless you want to make an atomic bomb which takes a lot of energy and you don’t want to destroy the whole world.
MIXTURE: Homogeneous VS. Heterogeneous:
Homo- mixed; cannot differentiate pieces
Hetero- can differentiate pieces
EX: homo- ketchup (can you see the difference in the vinegar and tomato paste? No)
Hetero- chicken noodle soup (there’s broth, chicken, peas, carrots, and other things)
