Answer:
The geologist time scale was formed when scientists studied rock layers and index fossils worldwide. With this information, they placed Earth's rocks in order by relative age. Later, radioactive dating helped determine the exact age of the divisons in the geologic time scale.
This scale is organized by the 4.6 billion years of earth's history into sections based on important changes seen in the geologic record. The largest intervals are called eons, with each eon containing many millions of years.
In precambarian time the processes that affect Earth's surface have lessened the erosion on the surface. Earth was being hit by meteorites every second. Now there is water erosion and there wasn't back then. The surface changes have lessened over time.
Answer:
4 grams
Explanation:
A = A₀e^⁻kt
A₀ = 125.0 grams
k= 0.693/t(1/2) = (0.693/68.8) yrs⁻¹ = 0.01 yrs⁻¹
t = 344.0 years
A = 125.0g·[e^-(0.01yrs⁻¹)(344.0yrs)] = 125(0.032)grams = 4.000g (4 sog. figs. based on A₀ = 125.0 grams)
Answer:
cellular respiration
Explanation:
All exergonic processes produced in the cell, through which substances oxidize and chemical energy is released, are grouped under the name of cellular respiration, but to break down an organic molecule the cells employ, mainly dehydrogenations that can be carried carried out in the presence or absence of atmospheric O2 oxygen. There are therefore two types of breathing: aerobic respiration and anaerobic respiration. The latter also called fermentation.
Aerobic respiration (oxidative phosphorylation)
- Use molecular O2.
- It degrades glucose to CO2 and H2O
- Exergonic
- Recovers about 50% of chemical energy
- Present in most organisms.
- It uses enzymes located in the mitochondria.
Answer: A: high ionization energies; high electron affinitlies.
Explanation: Covalent bonds are basically about sharing of electrons between two atoms to achieve that stable structure. They are formed between two atoms when both have similar tendencies to attract electrons to themselves (i.e., when both atoms have identical or fairly similar ionization energies and electron affinities). Covalent bonding usually occurs between two non-metals.
For effective and proper bonding, the two atoms involved in the covalent bonding exercise should be small and hungry for electrons. This is to enable the nuclei of both atoms to effectively attract and hold the shared electron(s) in place; hence, the need for high ionization energies & high electron affinities for a more effective covalent bonding.
Answer: Double displacement reaction
Explanation:
Double displacement reaction is defined as the reaction where exchange of ions takes place.
The salts which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid form are represented by (s) after their chemical formulas.
The chemical reaction between aqueous magnesium sulfate and aqueous sodium carbonate is represented as:
