How many days will it take for one half of the original amount of a radioactive substance to decay if the half-life is 30 days?

a. 3 days

b. 15 days

c. 30 days

d. 60 days

According to Einsteins explanation, what causes gravitation?

Which is an acid? A. CO is a gas at room temperature and has no odor. B. HCl has a sour taste and gives off protons in water. C. KOH has a bitter taste and accepts hydrogen ions.

How does brown algae move

The grains found in igneous rock: a. are cemented together c. are large b. form an interlocking texture d. will display in one-size only

A 1.50-m string of weight 0.0125 N is tied to the ceil - ing at its upper end, and the lower end supports a weight W. Ignore the very small variation in tension along the length of the string that is produced by the weight of the string.

a subsrance has an atomic number of 80. How many protons and electrons do atoms of the substance have? what is the subsance?

Ideal meters problem. What internal resistance is ideal for a voltmeter? What internal resistance is ideal for an ammeter?

numerical question : what is the required heat to raise the temperature of 2 kg parrafin by 10 Celsius if 44000 joules is required to raise it by 200 celsius

Psychologists avoid studying emotions because they have little impact on behavior T F

Sheila lives in the seashore community of Beachview. At 6:00 a. m. one morning, she noticed that the local ocean water was at high tide. At approximately noon that same day, she noticed the water was at low tide.