Moles of Na2SO4 = conc. x volume(dm3)
= 2 x (2500cm3/1000)
= 5 mol
Mass of Na2SO4 = moles x molar mass
= 5 x ((23 x 2) + 32.1 + (16 x 4))
= 710.5g
Answer:
- Option <u><em>d) isotope</em></u>.
Explanation:
All atoms of a same element have equal number of protons (atomic number) but <em>may</em> <em>differ in the number of neutrons.</em>
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The atoms that differ in the number of neutrons are named<em> isotopes</em>.
For example: carbon-12 and carbon-13 are diferent isotopes of the same element, carbon. They have the same number of protons (6, which is the atomic number of carbon). On the other hand, while carbon-12 has 6 neutrons, carbon-13 has 7 neutrons.
As per the other choices:
- a) <em>anions</em> are ions with negative charges: atoms (or group of atoms) that have gained one or more electrons.
- b) <em>cations</em> are ions with positive charge: atoms (or group of atoms) that have lost one or more electrons.
- e) <em>atoms</em> are the individual minimum parts of an element that preserves the properties of such element. All atoms of the same element have the same number of protons and have, essentially, the same chemical properties.
Answer:
C.It remains at rest or moves at constant speed in the same direction.
Explanation:
First, remember the Newton's 1st law of motion which states that the object at rest will remain at rest and that in motion will stay in motion with the same speed and same direction unless acted by unbalance forces.
Balanced forces on an object occur when two forces at act on an object are equal in size and act in opposite direction. In this case, a stationary object will stay at rest while an object moving will continue to move at the same speed and same direction.
An object acted by balanced forces is said to be at equilibrium, thus the state of motion will be maintained.The object will not accelerate. A good example of an object acted by balanced forces is an object at rest or in constant motion such as a car that stopped at red-light signal or a car travelling at a constant speed.
Answer:
Lungs
Explanation: The two organ systems that work together to provide the cells with oxygen and remove carbon dixoide from the body are the lungs.
Answer:
because they are actually moving, or because they reflect our motion through space.