Answer:
1.2 x 10⁵ moles Ag (2 sig. figs.)
Explanation:
1 mole any substance (elements or compounds) => 6.023 x 10²³ particles of specified substance
∴ 6.9 x 10²⁸ atoms Ag = 6.9 x 10²⁸ Ag atoms / 6.023 x 10²³ Ag atoms/mole Ag
= 1.145608501 x 10⁵ moles Ag (calculator answer)
= 1.2 x 10⁵ moles Ag (2 sig. figs.)
Answer:
Types of chemical weathering
1. Hydrolysis
2. Oxidation
3. Carbonation
4. Acid rain
5. Acids produced by lichens
Explanation:
Chemical weathering occurs when rocks undergo chemical reactions to form new minerals.
Hydrolysis : is when water dissolves minerals present in rocks forming new compounds.
Oxidation : is when oxygen reacts with rocks eg. rust formation
Carbonation : it uses an acid known as carbonic acid, it is important in the formation of many caves and sinkholes.
Answer:
KOH(aq) + HCI(aq) -----> KCI(aq )+ H2O
base acid salt water
hope this helps :)
Explanation:
Answer for number 1. Weight is the force of gravity. It acts in a downward direction—toward the center of the Earth.
Lift is the force that acts at a right angle to the direction of motion through the air. Lift is created by differences...
Thrust is the force that propels a flying machine in the direction of motion. Engines produce thrust.
2. For an airplane to takeoff, thrust must be greater than drag and lift must be greater than weight. To maintain level flight, lift must equal weight and thrust must equal drag. For landing, thrust must be less than drag, and lift must be less than weight.
3.When the forward forces are bigger than the opposing forces, you speed up (accelerate). As you go faster, the force of air resistance pushing back on you increases. Eventually, the forces become balanced (the forward forces are the same size as the opposing forces). Once the forces become balanced, your speed stays the same.
4.Every object on Earth has weight, a product of both gravity and mass. A Boeing 747-8 passenger airliner, for instance, has a maximum takeoff weight of 487.5 tons (442 metric tons), the force with which the weighty plane is drawn toward the Earth.
Answer:
a. in supernovae and star collisions
Explanation:
The periodical table contains some heavier elements, which are formed as neutron stars pairs hit eachother and erupt cataclysmically.
The star emitts very large quantities of energy and neutrons during supernova, which allow for the production of heavier elements than iron, such as uranium and gold. All these elements are ejected into space during the supernova explosion.