Sodium-24 has a half-life of 15 hours. After 45 hours, how much sodium-24 will remain of an original 50.0-g sample?

Which characteristic of enzymes allows it to be highly specific in the reactions they catalyze? its structure its concentration its diluted form its ability to replicate

A Carnot engine, operating between hot and cold reservoirs whose temperatures are 800.0 and 400.0 K, respectively, performs a certain amount of work W1. The temperature of the cold reservoir is then lowered to 200.

Mark needs to lower the pitch of the guitar to play his songs. How can Mark lower the pitch of the guitar? A Mark can make the strings tighter so they vibrate faster. B Mark can make the strings looser so they vibrate faster.

If an accident occurs in the laboratory, what is the first thing a student should do?

The velocity of a particle moving along the x axis is given for 1> 0 by v: = (32.0t - 2.00t^3) m/s, where t is in s. What is the acceleration of the particle when (after t = 0) it achieves its maximum displacement in the positive x direction?

Do you think Pluto should be considered a planet? Why or why not?

An object starts from rest at time t = 0.00 s and moves in the + x direction with constant acceleration. The object travels 14.0 m from time t = 1.00 s to time t = 2.00 s. What is the acceleration of the object? a) 5.20 m/s^2 b) 10.4 m/s^2 c) 8.

A box is dragged without acceleration in a straight-line path across a level surface by a force of 13 N. What is the frictional force between the box and the surface?

What is a wormhole, and how is it formed?

Most cells cannot harness heat to perform work because