Answer: 2. with two symmetrical shells - mirror images of each other.
the term "crinoid" means: 6. phylum where starfish and sea urchins belong
4. lived inside their shells: 1. exoskeletons are made up of this material
7. multicellular organisms that often live in colonies: 8. individuality of coral is called
Explanation:
Crinoid is a term that can be used to describe the radial symmetry of animals that have oral (side of mouth) and aboral surfaces (opposite to the mouth). It is characterized by the mouth at the top surface and surrounded by the arms for feeding it. This is a characteristic feature of animals like star fish and sea urchins and echinoderm animals.
The exoskeleton is a protective shell which protect the animal from the external environment like water, sunlight and predation.
The multicellular organisms that live in the colonies they form coral reef and individually the are called the coral polyp.
PH scale is used to determine how acidic or basic a solution is.
we have been given the hydrogen ion concentration. Using this we can calculate pH,
pH = - log[H⁺]
pH = - log (1 x 10⁻¹ M)
pH = 1
using pH can calculate pOH
pH + pOH = 14
pOH = 14 - 1
pOH = 13
using pOH we can calculate the hydroxide ion concentration
pOH = - log [OH⁻]
[OH⁻] = antilog(-pOH)
[OH⁻] = 10⁻¹³ M
hydroxide ion concentration is 10⁻¹³ M
1. true, more effective collisions per second. Faster reaction
2. <span>How can the reaction be slowed down? (talking about how fast or slow the reaction is)
</span>3. True
4. Rate lower if surface area decrease
5. Fine powder form
6. True
7. False
Image questions:
1. False
2. Energy of reactants higher than products.
Answer:
Change the temperature and pressure
Explanation:
In case we are analyzing the solubility of a salt in some solvent, raising the temperature would increase the solubility of a salt generally. In contrast, at lower temperatures the solubility of ionic salts would decrease.
Now, another variation of this scenario might be solubility of gases. According to Henry's Law, 
, meaning that the solubility of a gas is directly proportional to its partial pressure. Therefore, the greater the pressure, the greater the solubility of a gas.
Answer:
The correct answer is - (a) isobutene.
Explanation:
A 1° or primary hydrogen atom is one that is bonded to a 1° carbon atom; a 2° hydrogen atom is one that is connected to a 2° carbon atom; In isobutene only among all the all option having only primary hydrogen atoms. rest have secondary or teritary hydrogen atoms in them
C1∘H3≡CH: (only 1∘ hydrogen atoms)
